Human genetic engineering refers to the controlled modification of the human genome, which is the genome of Homo sapiens, composed of 23 pairs of chromosomes with a total of approximately 3 billion DNA base pairs containing an estimated 30,000 genes. DNA provides the genetic blueprint for all living organisms that influences the physical and mental actions and abilities. With the advent of DNA research and the ability to change gene expressions, it is now possible that scientists may be able to change human capacities, whether they be physical, cognitive, or emotional. Human genetic engineering is still in its infancy, however, with current research generally restricted to animals or gene therapy.
Healthy humans do not need gene therapy to survive (live a socially acceptable lifespan), though it may prove helpful to treat certain diseases. Special gene modification research has been carried out on groups such as the 'bubble children' - those whose immune systems do not protect them from the bacteria and irritants all around them. The first clinical trial of human gene therapy began in 1990, but (as of 2006) is still experimental. Other forms of human genetic engineering are still theoretical, or restricted to fiction stories. Recombinant DNA research is usually performed to study gene expression and various human diseases. Some drastic demonstrations of gene modification have been made with mice and other animals, however; testing on humans is generally considered off-limits. In some instances changes are usually brought about by removing genetic material from one organism and transferring them into another species, method is known as recombinant genetics.
Thursday, March 27, 2008
What are the Two main types of Genetic Engineering?
There are two main types of genetic engineering. Somatic modifications involve adding genes to cells other than egg or sperm cells. For example, if a person had a disease caused by a defective gene, a healthy gene could be added to the affected cells to treat the disorder. The distinguishing characteristic of somatic engineering is that it is non-inheritable, e.g. the new gene would not be passed to the recipient’s offspring.
Germline engineering would change genes in eggs, sperm, or very early embryos. This type of engineering is inheritable, meaning that the modified genes would appear not only in any children that resulted from the procedure, but in all succeeding generations. This application is by far the more consequential as it could open the door to the perpetual and irreversible alteration of the human species.
There are two techniques researchers are currently experimenting with:
Viruses are good at injecting their DNA payload into human cells and reproducing it. By adding the desired DNA to the DNA of non-pathogenic virus, a small amount of virus will reproduce the desired DNA and spread it all over the body.
Manufacture large quantities of DNA, and somehow package it to induce the target cells to accept it, either as an addition to one of the original 23 chromosomes, or as an independent 24th human artificial chromosome.
Human genetic engineering means that some part of the genes or DNA of a person are changed. It is possible that through engineering, people could be given more arms, bigger brains, or other structural alteration such as fins if desired. A more common type of change would be finding the genes of extraordinary people - such as those for intelligence, stamina, longevity, and incorporating those in embryos. Human genetic engineering holds the promise of being able to cure diseases and increasing the immunity of people to virus. Disorders such as Cystic fibrosis, which is a genetic disease that affects lungs and other organs is the result of small DNA changes.
Germline engineering would change genes in eggs, sperm, or very early embryos. This type of engineering is inheritable, meaning that the modified genes would appear not only in any children that resulted from the procedure, but in all succeeding generations. This application is by far the more consequential as it could open the door to the perpetual and irreversible alteration of the human species.
There are two techniques researchers are currently experimenting with:
Viruses are good at injecting their DNA payload into human cells and reproducing it. By adding the desired DNA to the DNA of non-pathogenic virus, a small amount of virus will reproduce the desired DNA and spread it all over the body.
Manufacture large quantities of DNA, and somehow package it to induce the target cells to accept it, either as an addition to one of the original 23 chromosomes, or as an independent 24th human artificial chromosome.
Human genetic engineering means that some part of the genes or DNA of a person are changed. It is possible that through engineering, people could be given more arms, bigger brains, or other structural alteration such as fins if desired. A more common type of change would be finding the genes of extraordinary people - such as those for intelligence, stamina, longevity, and incorporating those in embryos. Human genetic engineering holds the promise of being able to cure diseases and increasing the immunity of people to virus. Disorders such as Cystic fibrosis, which is a genetic disease that affects lungs and other organs is the result of small DNA changes.
Germline
In biology and genetics, the germline of a mature or developing individual is the line (sequence) of germ cells that have genetic material that may be passed to a child.
For example, sex cells, such as the sperm or the egg, are part of the germline. So are the cells that produce sex cells, called gametocytes, the cells that produce those, called gametogonia, and all the way back to the zygote, the cell from which the individual developed.
Cells that are not in the germline are called somatic cells. For example, all cells of the mammalian liver are somatic. If there is a mutation or other genetic change in the germline, it can be passed to offspring, but a change in a somatic cell will not be.
Germline cells are immortal, in the sense that they can reproduce indefinitely. This is enabled by a special enzyme called telomerase. This enzyme is dedicated to lengthening the DNA primer of the chromosome, allowing for unending duplication. Somatic cells, by comparison, can only divide around 30-50 times, as they do not contain telomerases.
"Germline" can refer to a lineage of cells spanning many generations of individuals; for example, the germline that links any living individual to the hypothetical first eukaryote of about one billion years ago, from which all plants and animals descend.
For example, sex cells, such as the sperm or the egg, are part of the germline. So are the cells that produce sex cells, called gametocytes, the cells that produce those, called gametogonia, and all the way back to the zygote, the cell from which the individual developed.
Cells that are not in the germline are called somatic cells. For example, all cells of the mammalian liver are somatic. If there is a mutation or other genetic change in the germline, it can be passed to offspring, but a change in a somatic cell will not be.
Germline cells are immortal, in the sense that they can reproduce indefinitely. This is enabled by a special enzyme called telomerase. This enzyme is dedicated to lengthening the DNA primer of the chromosome, allowing for unending duplication. Somatic cells, by comparison, can only divide around 30-50 times, as they do not contain telomerases.
"Germline" can refer to a lineage of cells spanning many generations of individuals; for example, the germline that links any living individual to the hypothetical first eukaryote of about one billion years ago, from which all plants and animals descend.
What is Somatic Engineering?
The term somatic refers to the holistic relationship of the body and mind. The word comes from the Greek word Σωματικóς (Somatikòs), meaning "of the body". It has different meanings in various disciplines.
Thomas Hanna originated this usage of the term. He defined a soma as "the body as experienced and directed from within", or the subjective experience of embodiment, as opposed to the body as viewed from an external viewpoint.
In neurobiology, somatic can be an adjective referring to the soma, the part of the neuron containing the cell nucleus.
In anatomy, somatic can refer to the part of the nervous system that controls voluntary movement and sensation and judges relative effort and weight, called proprioception. Additionally, somatic muscles are basically those of the musculo-skeletal system.
In genetics, somatic can refer to a cell or tissue that resides outside the germline (see somatic cell). For example, a somatic mutation cannot be transmitted to descendants in animals.
In the philosophy of education, the idea that mind and body are intrinsically interdependent aspects of a whole human being somatics. According to the originator of this usage of the term, "somatic awareness allows a person to glean wisdom from within.The usage of somatic as put forth by Thomas Hanna implies a truly integrated mind/body/spirit nature of humans. Thus far, the popular usage of this term has not fully realized this meaning, and a mind-body dualism still often occurs in disciplines describing themselves as somatic. Hanna Somatics is the educational practice developed by Hanna which enhances sensory awareness and motor control in those who practice it.
Thomas Hanna originated this usage of the term. He defined a soma as "the body as experienced and directed from within", or the subjective experience of embodiment, as opposed to the body as viewed from an external viewpoint.
In neurobiology, somatic can be an adjective referring to the soma, the part of the neuron containing the cell nucleus.
In anatomy, somatic can refer to the part of the nervous system that controls voluntary movement and sensation and judges relative effort and weight, called proprioception. Additionally, somatic muscles are basically those of the musculo-skeletal system.
In genetics, somatic can refer to a cell or tissue that resides outside the germline (see somatic cell). For example, a somatic mutation cannot be transmitted to descendants in animals.
In the philosophy of education, the idea that mind and body are intrinsically interdependent aspects of a whole human being somatics. According to the originator of this usage of the term, "somatic awareness allows a person to glean wisdom from within.The usage of somatic as put forth by Thomas Hanna implies a truly integrated mind/body/spirit nature of humans. Thus far, the popular usage of this term has not fully realized this meaning, and a mind-body dualism still often occurs in disciplines describing themselves as somatic. Hanna Somatics is the educational practice developed by Hanna which enhances sensory awareness and motor control in those who practice it.
What is Human artificial chromosome?
A human artificial chromosome (HAC) is a microchromosome that can act as a new chromosome in a population of human cells. That is, instead of 46 chromosomes, the cell could have 47 with the 47th being very small, roughly 6-10 megabases in size, and able to carry new genes introduced by human researchers. Yeast artificial chromosomes and bacterial artificial chromosomes were invented before human artificial chromosomes, which first appeared in 1997. They are useful in expression studies as gene transfer vectors and are a tool for elucidating human chromosome function. Grown in HT1080 cells, they are mitotically and cytogenetically stable for up to six months.
Gene expression
Gene expression is the process by which inheritable information from a gene, such as the DNA sequence, is made into a functional gene product, such as protein or RNA.
Several steps in the gene expression process may be modulated, including the transcription step and the post-translational modification of a protein. Gene regulation gives the cell control over structure and function, and is the basis for cellular differentiation, morphogenesis and the versatility and adaptability of any organism. Gene regulation may also serve as a substrate for evolutionary change, since control of the timing, location, and amount of gene expression can have a profound effect on the functions (actions) of the gene in the organism.
Non-protein coding genes (e.g. rRNA genes, tRNA genes) are not translated into protein.
Several steps in the gene expression process may be modulated, including the transcription step and the post-translational modification of a protein. Gene regulation gives the cell control over structure and function, and is the basis for cellular differentiation, morphogenesis and the versatility and adaptability of any organism. Gene regulation may also serve as a substrate for evolutionary change, since control of the timing, location, and amount of gene expression can have a profound effect on the functions (actions) of the gene in the organism.
Non-protein coding genes (e.g. rRNA genes, tRNA genes) are not translated into protein.
Genetic engineering
Genetic engineering, recombinant DNA technology, genetic modification/manipulation (GM) and gene splicing are terms that are applied to the direct manipulation of an organism's genes. Genetic engineering is not to be confused with traditional breeding where the organism's genes are manipulated indirectly. Genetic engineering uses the techniques of molecular cloning and transformation. Genetic engineering endeavors have found some success in improving crop technology, the manufacture of synthetic human insulin through the use of modified bacteria, the manufacture of erythropoietin in Chinese hamster ovary cells, and the production of new types of experimental mice such as the oncomouse (cancer mouse) for research.
Since a protein sequence is specified by a segment of DNA called a gene, novel versions of that protein can be produced by changing the DNA sequence of the gene. Some groups have argued that genetic engineering is wrong and is "doing the work of God", but most scientists believe that genetic engineering is essential to help future medical discoveries.
However, even with regard to this technology's great potential, some people have raised concerns about the introduction of genetically engineered plants and animals into the environment and the potential dangers of human consumption of GM foods. They say that these organisms have the potential to spread their modified genes into native populations thereby disrupting natural ecosystems. See also GM food controversies, and genetically modified organism (GMO) for more information on GM controversies.
Since a protein sequence is specified by a segment of DNA called a gene, novel versions of that protein can be produced by changing the DNA sequence of the gene. Some groups have argued that genetic engineering is wrong and is "doing the work of God", but most scientists believe that genetic engineering is essential to help future medical discoveries.
However, even with regard to this technology's great potential, some people have raised concerns about the introduction of genetically engineered plants and animals into the environment and the potential dangers of human consumption of GM foods. They say that these organisms have the potential to spread their modified genes into native populations thereby disrupting natural ecosystems. See also GM food controversies, and genetically modified organism (GMO) for more information on GM controversies.
Recombinant DNA
Recombinant DNA is a form of artificial DNA that is engineered through the combination or insertion of one or more DNA strands, thereby combining DNA sequences that would not normally occur together. In terms of genetic modification, recombinant DNA is produced through the addition of relevant DNA into an existing organismal genome, such as the plasmid of bacteria, to code for or alter different traits for a specific purpose, such as immunity. It differs from genetic recombination, in that it does not occur through processes within the cell or ribosome, but is exclusively engineered.The Recombinant DNA technique was engineered by Stanley Norman Cohen and Herbert Boyer in 1973. They published their findings in a 1974 paper entitled "Construction of Biologically Functional Bacterial Plasmids in vitro", which described a technique to isolate and amplify genes or DNA segments and insert them into another cell with precision, creating a transgenic bacterium
DNA
Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information.
Chemically, DNA is a long polymer of simple units called nucleotides, with a backbone made of sugars and phosphate groups joined by ester bonds. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a process called transcription.
Within cells, DNA is organized into structures called chromosomes. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic organisms (animals, plants, and fungi) store their DNA inside the cell nucleus, while in prokaryotes (bacteria and archae) it is found in the cell's cytoplasm. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.
Chemically, DNA is a long polymer of simple units called nucleotides, with a backbone made of sugars and phosphate groups joined by ester bonds. Attached to each sugar is one of four types of molecules called bases. It is the sequence of these four bases along the backbone that encodes information. This information is read using the genetic code, which specifies the sequence of the amino acids within proteins. The code is read by copying stretches of DNA into the related nucleic acid RNA, in a process called transcription.
Within cells, DNA is organized into structures called chromosomes. These chromosomes are duplicated before cells divide, in a process called DNA replication. Eukaryotic organisms (animals, plants, and fungi) store their DNA inside the cell nucleus, while in prokaryotes (bacteria and archae) it is found in the cell's cytoplasm. Within the chromosomes, chromatin proteins such as histones compact and organize DNA. These compact structures guide the interactions between DNA and other proteins, helping control which parts of the DNA are transcribed.
Chromosome
Chromosomes are organized structures of DNA and proteins that are found in cells. Chromosomes contain a single continuous piece of DNA, which contains many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions. The word chromosome comes from the Greek χρῶμα (chroma, color) and σῶμα (soma, body) due to their property of being stained very strongly by some dyes.
Chromosomes vary extensively between different organisms. The DNA molecule may be circular or linear, and can contain anything from tens of kilobase pairs to hundreds of megabase pairs. Typically eukaryotic cells (cells with nuclei) have large linear chromosomes and prokaryotic cells (cells without defined nuclei) have smaller circular chromosomes, although there are many exceptions to this rule. Furthermore, cells may contain more than one type of chromosome; for example mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosomes.
In eukaryotes, nuclear chromosomes are packaged by proteins into a condensed structure called chromatin. This allows the massively-long DNA molecules to fit into the cell nucleus. The structure of chromatin varies through the cell cycle, and is responsible for the organization of chromosomes into the classic four-arm structure during mitosis and meiosis.
"Chromosome" is a rather loosely defined term. In prokaryotes, a small circular DNA molecule may be called either a plasmid or a small chromosome. These small circular genomes are also found in mitochondria and chloroplasts, reflecting their bacterial origins. The simplest chromosomes are found in viruses: these DNA or RNA molecules are short linear or circular chromosomes that often lack any structural proteins
Chromosomes vary extensively between different organisms. The DNA molecule may be circular or linear, and can contain anything from tens of kilobase pairs to hundreds of megabase pairs. Typically eukaryotic cells (cells with nuclei) have large linear chromosomes and prokaryotic cells (cells without defined nuclei) have smaller circular chromosomes, although there are many exceptions to this rule. Furthermore, cells may contain more than one type of chromosome; for example mitochondria in most eukaryotes and chloroplasts in plants have their own small chromosomes.
In eukaryotes, nuclear chromosomes are packaged by proteins into a condensed structure called chromatin. This allows the massively-long DNA molecules to fit into the cell nucleus. The structure of chromatin varies through the cell cycle, and is responsible for the organization of chromosomes into the classic four-arm structure during mitosis and meiosis.
"Chromosome" is a rather loosely defined term. In prokaryotes, a small circular DNA molecule may be called either a plasmid or a small chromosome. These small circular genomes are also found in mitochondria and chloroplasts, reflecting their bacterial origins. The simplest chromosomes are found in viruses: these DNA or RNA molecules are short linear or circular chromosomes that often lack any structural proteins
Human
Humans, or human beings, are bipedal primates belonging to the mammalian species Homo sapiens (Latin: "wise man" or "knowing man") in the family Hominidae (the great apes).Compared to other species, humans have a highly developed brain capable of abstract reasoning, language, and introspection. This mental capability, combined with an erect body carriage that frees their upper limbs for manipulating objects, has allowed humans to make far greater use of tools than any other species. DNA evidence indicates that modern humans originated in Africa about 200,000 years ago.Humans now inhabit every continent and low Earth orbit, with a total population of over 6.7 billion as of March 2008.Like most primates, humans are social by nature. However, humans are particularly adept at utilizing systems of communication for self-expression, the exchange of ideas, and organization. Humans create complex social structures composed of many cooperating and competing groups, from families to nations. Social interactions between humans have established an extremely wide variety of traditions, rituals, ethics, values, social norms, and laws which form the basis of human society. Humans have a marked appreciation for beauty and aesthetics which, combined with the human desire for self-expression, has led to cultural innovations such as art, literature and music.
Humans are noted for their desire to understand and influence the world around them, seeking to explain and manipulate natural phenomena through science, philosophy, mythology and religion. This natural curiosity has led to the development of advanced tools and skills; humans are the only extant species known to build fires, cook their food, clothe themselves, and use numerous other technologies.
Humans are noted for their desire to understand and influence the world around them, seeking to explain and manipulate natural phenomena through science, philosophy, mythology and religion. This natural curiosity has led to the development of advanced tools and skills; humans are the only extant species known to build fires, cook their food, clothe themselves, and use numerous other technologies.
Human genome
The human genome is the genome of Homo sapiens, which is stored on 24 distinct chromosomes (22 autosomal + X + Y) containing an estimated 20,000–25,000 genes.The entire human genome occupies a total of just over 3 billion DNA base pairs, and has a data size of approximately 750 Megabytes. which is slightly larger than the capacity of a standard Compact Disc.
The Human Genome Project has produced a reference sequence of the euchromatic human genome, which is used worldwide in biomedical sciences. The human genome had fewer genes than expected, with only about 1.5% coding for proteins, and the rest comprised by RNA genes, regulatory sequences, introns and controversially so-called junk DNA
The Human Genome Project has produced a reference sequence of the euchromatic human genome, which is used worldwide in biomedical sciences. The human genome had fewer genes than expected, with only about 1.5% coding for proteins, and the rest comprised by RNA genes, regulatory sequences, introns and controversially so-called junk DNA
Infertility
Infertility primarily refers to the biological inability of a man or a woman to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term. There are many biological causes of infertility, some which may be bypassed with medical intervention.Women who are fertile experience a natural period of fertility before and during ovulation, and they are naturally infertile during th
e rest of the menstrual cycle. Fertility awareness methods are used to discern when these changes occur; by tracking changes in cervical mucus or basal body temperature
e rest of the menstrual cycle. Fertility awareness methods are used to discern when these changes occur; by tracking changes in cervical mucus or basal body temperatureEndocrine disease and growth
The pancreas contains the islets of Langerhans, which are responsible for making insulin, a hormone that helps regulate blood glucose. Damage of the pancreas can lead to loss of the islet cells, leading to diabetes that is unique to those with the disease. Cystic Fibrosis Related Diabetes (CFRD), as it is known as, shares characteristics that can be found in Type 1 and Type 2 diabetics and is one of the principal non-pulmonary complications of CF. Vitamin D is involved in calcium and phosphorus regulation. Poor uptake of vitamin D from the diet because of malabsorption leads to the bone disease osteoporosis in which weakened bones are more susceptible to fractures.In addition, people with CF often develop clubbing of their fingers and toes due to the effects of chronic illness and low oxygen on their tissues.
Poor growth is a hallmark of CF. Children with CF typically do not gain weight or height at the same rate as their peers, and occasionally are not diagnosed until investigation is initiated for poor growth. The causes of growth failure are multi–factorial and include chronic lung infection, poor absorption of nutrients through the gastrointestinal tract, and increased metabolic demand due to chronic illness.
Poor growth is a hallmark of CF. Children with CF typically do not gain weight or height at the same rate as their peers, and occasionally are not diagnosed until investigation is initiated for poor growth. The causes of growth failure are multi–factorial and include chronic lung infection, poor absorption of nutrients through the gastrointestinal tract, and increased metabolic demand due to chronic illness.
Gastrointestinal, liver and pancreatic disease
Prior to prenatal and newborn screening, cystic fibrosis was often diagnosed when a newborn infant failed to pass faeces (meconium). Meconium may completely block the intestines and cause serious illness. This condition, called meconium ileus, occurs in 10% of newborns with CF. In addition, protrusion of internal rectal membranes (rectal prolapse) is more common in CF because of increased fecal volume, malnutrition, and increased intra–abdominal pressure due to coughing.The thick mucus seen in the lungs has its counterpart in thickened secretions from the pancreas, an organ responsible for providing digestive juices which help break down food. These secretions block the movement of the digestive enzymes into the duodenum and result in irreversible damage to the pancreas, often with painful inflammation (pancreatitis). The lack of digestive enzymes leads to difficulty absorbing nutrients with their subsequent excretion in the faeces, a disorder known as malabsorption. Malabsorption leads to malnutrition and poor growth and development because of calorie loss. Individuals with CF also have difficulties absorbing the fat-soluble vitamins A, D, E, and K. In addition to the pancreas problems, people with cystic fibrosis experience more heartburn, intestinal blockage by intussusception, and constipation.. Older individuals with CF may also develop distal intestinal obstruction syndrome when thickened faeces cause intestinal blockage.Thickened secretions also may cause liver problems in patients with CF. Bile secreted by the liver to aid in digestion may block the bile ducts, leading to liver damage. Over time, this can lead to cirrhosis, in which the liver fails to rid the blood of toxins and does not make important proteins such as those responsible for blood clotting.
Symptomatic diseases
Lung and sinus disease
Lung disease results from clogging of airways due to inflammation. Inflammation and infection cause injury to the lungs and structural changes that lead to a variety of symptoms. In the early stages, incessant coughing, copious phlegm production, and decreased ability to exercise are common. Many of these symptoms occur when bacteria that normally inhabit the thick mucus grow out of control and cause pneumonia. In later stages of CF, changes in the architecture of the lung further exacerbate chronic difficulties in breathing.
Aspergillus fumigatus - A common fungus which can lead to worsening lung disease in people with CF
Other symptoms include coughing up blood (hemoptysis), changes in the major airways in the lungs (bronchiectasis), high blood pressure in the lung (pulmonary hypertension), heart failure, difficulties getting enough oxygen to the body (hypoxia), and respiratory failure requiring support with breathing masks such as bilevel positive airway pressure machines or ventilators In addition to typical bacterial infections, people with CF more commonly develop other types of lung disease. Among these is allergic bronchopulmonary aspergillosis, in which the body's response to the common fungus Aspergillus fumigatus causes worsening of breathing problems. Another is infection with mycobacterium avium complex (MAC), a group of bacteria related to tuberculosis, which can cause further lung damage and does not respond to common antibiotics.
Mucus in the paranasal sinuses is equally thick and may also cause blockage of the sinus passages, leading to infection. This may cause facial pain, fever, nasal drainage, and headaches. Individuals with CF may develop overgrowth of the nasal tissue (nasal polyps) due to inflammation from chronic sinus infections. These polyps can block the nasal passages and increase breathing difficulties.
Lung disease results from clogging of airways due to inflammation. Inflammation and infection cause injury to the lungs and structural changes that lead to a variety of symptoms. In the early stages, incessant coughing, copious phlegm production, and decreased ability to exercise are common. Many of these symptoms occur when bacteria that normally inhabit the thick mucus grow out of control and cause pneumonia. In later stages of CF, changes in the architecture of the lung further exacerbate chronic difficulties in breathing.
Aspergillus fumigatus - A common fungus which can lead to worsening lung disease in people with CF
Other symptoms include coughing up blood (hemoptysis), changes in the major airways in the lungs (bronchiectasis), high blood pressure in the lung (pulmonary hypertension), heart failure, difficulties getting enough oxygen to the body (hypoxia), and respiratory failure requiring support with breathing masks such as bilevel positive airway pressure machines or ventilators In addition to typical bacterial infections, people with CF more commonly develop other types of lung disease. Among these is allergic bronchopulmonary aspergillosis, in which the body's response to the common fungus Aspergillus fumigatus causes worsening of breathing problems. Another is infection with mycobacterium avium complex (MAC), a group of bacteria related to tuberculosis, which can cause further lung damage and does not respond to common antibiotics.
Mucus in the paranasal sinuses is equally thick and may also cause blockage of the sinus passages, leading to infection. This may cause facial pain, fever, nasal drainage, and headaches. Individuals with CF may develop overgrowth of the nasal tissue (nasal polyps) due to inflammation from chronic sinus infections. These polyps can block the nasal passages and increase breathing difficulties.
Cystic fibrosis
Cystic fibrosis (also known as CF, mucoviscoidosis, or mucoviscidosis) is a hereditary disease that affects mainly the lungs and digestive system, causing progressive disability.
Thick mucus production, as well as a less competent immune system, results in frequent lung infections. Diminished secretion of pancreatic enzymes is the main cause of poor growth, fatty diarrhea and deficiency in fat-soluble vitamins. Males can be infertile due to the condition congenital bilateral absence of the vas deferens. Often, symptoms of CF appear in infancy and childhood. Meconium ileus is a typical finding in newborn babies with CF.
Individuals with cystic fibrosis can be diagnosed prior to birth by genetic testing. Newborn screening tests are increasingly common and effective. The diagnosis of CF may be confirmed if high levels of salt are found during a sweat test, although some false positives may occur.
There is no cure for CF, and most individuals with cystic fibrosis die young: many in their 20s and 30s from lung failure. However, with the continuous introduction of many new treatments, the life expectancy of a person with CF is increasing. Lung transplantation is often necessary as CF worsens.
Cystic fibrosis is one of the most common life-shortening, childhood-onset inherited diseases. In the United States, 1 in 3900 children are born with CF.It is most common among Europeans and Ashkenazi Jews; one in twenty-two people of European descent are carriers of one gene for CF, making it the most common genetic disease in these populations. Ireland has the highest rate of CF carriers in the world (1 in 19).
CF is caused by a mutation in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR). The product of this gene is a chloride ion channel important in creating sweat, digestive juices, and mucus. Although most people without CF have two working copies of the CFTR gene, only one is needed to prevent cystic fibrosis. CF develops when neither gene can produce a functional CFTR protein. Therefore, CF is considered an autosomal recessive disease.
Thick mucus production, as well as a less competent immune system, results in frequent lung infections. Diminished secretion of pancreatic enzymes is the main cause of poor growth, fatty diarrhea and deficiency in fat-soluble vitamins. Males can be infertile due to the condition congenital bilateral absence of the vas deferens. Often, symptoms of CF appear in infancy and childhood. Meconium ileus is a typical finding in newborn babies with CF.
Individuals with cystic fibrosis can be diagnosed prior to birth by genetic testing. Newborn screening tests are increasingly common and effective. The diagnosis of CF may be confirmed if high levels of salt are found during a sweat test, although some false positives may occur.
There is no cure for CF, and most individuals with cystic fibrosis die young: many in their 20s and 30s from lung failure. However, with the continuous introduction of many new treatments, the life expectancy of a person with CF is increasing. Lung transplantation is often necessary as CF worsens.
Cystic fibrosis is one of the most common life-shortening, childhood-onset inherited diseases. In the United States, 1 in 3900 children are born with CF.It is most common among Europeans and Ashkenazi Jews; one in twenty-two people of European descent are carriers of one gene for CF, making it the most common genetic disease in these populations. Ireland has the highest rate of CF carriers in the world (1 in 19).
CF is caused by a mutation in a gene called the cystic fibrosis transmembrane conductance regulator (CFTR). The product of this gene is a chloride ion channel important in creating sweat, digestive juices, and mucus. Although most people without CF have two working copies of the CFTR gene, only one is needed to prevent cystic fibrosis. CF develops when neither gene can produce a functional CFTR protein. Therefore, CF is considered an autosomal recessive disease.
Transmission of pathogens
One of the primary pathways by which food or water become contaminated is from the release of untreated sewage into a drinking water supply or onto cropland, with the result that people who eat or drink contaminated sources become infected. In developing countries most sewage is discharged into the environment or on cropland as of 12 August 1985; even in developed countries there are periodic system failures resulting in a sanitary sewer overflow. This is the typical mode of transmission for the infectious agents of (at least):
Cholera
Hepatitis A
Polio
Rotavirus
Cholera
Hepatitis A
Polio
Rotavirus
Pathogenic bacteria
Although the vast majority of bacteria are harmless or beneficial, a few pathogenic bacteria cause infectious diseases. The most common bacterial disease is tuberculosis, caused by the bacterium Mycobacterium tuberculosis, which kills about 2 million people a year, mostly in sub-Saharan Africa. Pathogenic bacteria contribute to other globally important diseases, such as pneumonia, which can be caused by bacteria such as Streptococcus and Pseudomonas, and foodborne illnesses, which can be caused by bacteria such as Shigella, Campylobacter and Salmonella. Pathogenic bacteria also cause infections such as tetanus, typhoid fever, diphtheria, syphilis and leprosy
What is Pathogen?
A pathogen (from Greek pathos, suffering/emotion, and gene, to give birth to), infectious agent, or more commonly germ, is a biological agent that causes disease or illness to its host.[1] The term is most often used for agents that disrupt the normal physiology of a multicellular animal or plant. However, pathogens can infect unicellular organisms from all of the biological kingdoms. The term pathogen is derived from the Greek παθογένεια, "that which produces suffering." There are several substrates and pathways where by pathogens can invade a host; the principal pathways have different episodic time frames, but soil contamination has the longest or most persistent potential for harboring a pathogen.
The body contains many natural defenses against some of the common pathogens (such as Pneumocystis) in the form of the human immune system and by some "helpful" bacteria present in the human body's normal flora. However, if the immune system or "good" bacteria is damaged in any way (such as by chemotherapy, human immunodeficiency virus (HIV), or antibiotics being taken to kill other pathogens), pathogenic bacteria that were being held at bay can proliferate and cause harm to the host. Such cases are called opportunistic infections.
Some pathogens (such as the bacterium Yersinia pestis, which may have caused the Black Plague, the Variola virus, and the Malaria protozoa) have been responsible for massive numbers of casualties and have had numerous effects on afflicted groups. Of particular note in modern times is HIV, which is known to have infected several million humans globally, along with Severe Acute Respiratory Syndrome (SARS) and the Influenza virus. Today, while many medical advances have been made to safeguard against infection by pathogens, through the use of vaccination, antibiotics, and fungicide, pathogens continue to threaten human life. Social advances such as food safety, hygiene, and water treatment have reduced the threat from some pathogens.
The body contains many natural defenses against some of the common pathogens (such as Pneumocystis) in the form of the human immune system and by some "helpful" bacteria present in the human body's normal flora. However, if the immune system or "good" bacteria is damaged in any way (such as by chemotherapy, human immunodeficiency virus (HIV), or antibiotics being taken to kill other pathogens), pathogenic bacteria that were being held at bay can proliferate and cause harm to the host. Such cases are called opportunistic infections.
Some pathogens (such as the bacterium Yersinia pestis, which may have caused the Black Plague, the Variola virus, and the Malaria protozoa) have been responsible for massive numbers of casualties and have had numerous effects on afflicted groups. Of particular note in modern times is HIV, which is known to have infected several million humans globally, along with Severe Acute Respiratory Syndrome (SARS) and the Influenza virus. Today, while many medical advances have been made to safeguard against infection by pathogens, through the use of vaccination, antibiotics, and fungicide, pathogens continue to threaten human life. Social advances such as food safety, hygiene, and water treatment have reduced the threat from some pathogens.
Types of gene therapy
Germ line gene therapy
In the case of germ line gene therapy, germ cells, i.e., sperm or eggs, are modified by the introduction of functional genes, which are ordinarily integrated into their genomes. Therefore, the change due to therapy would be heritable and would be passed on to later generations. This new approach, theoretically, should be highly effective in counteracting genetic disorders. However, this option is prohibited for application in human beings, at least for the present, for a variety of technical and ethical reasons.
Somatic cell gene therapy
In somatic cell gene therapy, the gene is introduced only in somatic cells, especially of these tissues in which expression of the concerned gene is critical for health. Expression of the introduced gene relieves/ eliminates symptoms of the disorder, but this effect is not heritable as it does not involve the germ line. At present, somatic cell therapy is the only feasible option, and clinical trials addressing a variety of conditions have already begun
In the case of germ line gene therapy, germ cells, i.e., sperm or eggs, are modified by the introduction of functional genes, which are ordinarily integrated into their genomes. Therefore, the change due to therapy would be heritable and would be passed on to later generations. This new approach, theoretically, should be highly effective in counteracting genetic disorders. However, this option is prohibited for application in human beings, at least for the present, for a variety of technical and ethical reasons.
Somatic cell gene therapy
In somatic cell gene therapy, the gene is introduced only in somatic cells, especially of these tissues in which expression of the concerned gene is critical for health. Expression of the introduced gene relieves/ eliminates symptoms of the disorder, but this effect is not heritable as it does not involve the germ line. At present, somatic cell therapy is the only feasible option, and clinical trials addressing a variety of conditions have already begun
Gene Therapy
Gene therapy is the insertion of genes into an individual's cells and tissues to treat a disease, and hereditary diseases in which a defective mutant allele is replaced with a functional one. Although the technology is still in its infancy, it has been used with some success. Antisense therapy is not strictly a form of gene therapy, but is a genetically-mediated therapy and is often considered together with other methods
Applications of Human Genetic Engineering
Curing medical conditions
When treating problems that arise from genetic disorder, one solution is gene therapy. A genetic disorder is a situation where some genes are missing or faulty. When this happens, genes may be expressed in unfavorable ways or not at all, and this generally leads to further complications.
The idea of gene therapy is that a non-pathogenic virus or other delivery system can be used to insert a piece of DNA--a good copy of the gene--into cells of the living individual. The modified cells would divide as normal and each division would produce cells that express the desired trait. The result would be that he/she would then have the ability to express the trait that was previously absent at least partially. This form of genetic engineering could help alleviate many problems, such as diabetes, cystic fibrosis, or other genetic diseases.
Human enhancement
Main article: Human enhancement
The potential of genetic engineering to cure medical conditions opens the question of exactly what such a condition is. Some view aging and death as medical conditions and therefore potential targets for engineering solutions. They see human genetic engineering potentially as a key tool in this (see life extension). The difference between cure and enhancement from this perspective is merely one of degree. Theoretically genetic engineering could be used to drastically change people's genomes, which could enable people to regrow limbs and other organs, perhaps even extremely complex ones such as the spine. It could also be used to make people stronger, faster, smarter, or to increase the capacity of the lungs, among other things. If a gene exists in nature, it could be brought over to a human cell. In this view, there is no qualitative difference (only a quantitative one) between, for instance, a genetic intervention to cure muscular dystrophy, and a genetic intervention to improve muscle function even when those muscles are functioning at or around the human average (since there is also an average muscle function for those with a particular type of dystrophy, which the treatment would improve upon).
Others feel that there is an important distinction between using genetic technologies to treat those who are suffering and to make those who are already healthy superior to the average. There is widespread agreement that germline engineering should not currently be allowed for either therapeutic and enhancement applications, as evidenced by a recent report by the American Association for the Advancement of Science. .Though theory and speculation suggest that genetic engineering could be used to make people stronger, faster, smarter, or to increase lung capacity, the AAAS report finds that there is little evidence that this can currently be done without very unsafe and therefore unethical human experiments. Because different cells have different tasks, changing one cell to do a different job will not only affect that one task, it can affect many others too
When treating problems that arise from genetic disorder, one solution is gene therapy. A genetic disorder is a situation where some genes are missing or faulty. When this happens, genes may be expressed in unfavorable ways or not at all, and this generally leads to further complications.
The idea of gene therapy is that a non-pathogenic virus or other delivery system can be used to insert a piece of DNA--a good copy of the gene--into cells of the living individual. The modified cells would divide as normal and each division would produce cells that express the desired trait. The result would be that he/she would then have the ability to express the trait that was previously absent at least partially. This form of genetic engineering could help alleviate many problems, such as diabetes, cystic fibrosis, or other genetic diseases.
Human enhancement
Main article: Human enhancement
The potential of genetic engineering to cure medical conditions opens the question of exactly what such a condition is. Some view aging and death as medical conditions and therefore potential targets for engineering solutions. They see human genetic engineering potentially as a key tool in this (see life extension). The difference between cure and enhancement from this perspective is merely one of degree. Theoretically genetic engineering could be used to drastically change people's genomes, which could enable people to regrow limbs and other organs, perhaps even extremely complex ones such as the spine. It could also be used to make people stronger, faster, smarter, or to increase the capacity of the lungs, among other things. If a gene exists in nature, it could be brought over to a human cell. In this view, there is no qualitative difference (only a quantitative one) between, for instance, a genetic intervention to cure muscular dystrophy, and a genetic intervention to improve muscle function even when those muscles are functioning at or around the human average (since there is also an average muscle function for those with a particular type of dystrophy, which the treatment would improve upon).
Others feel that there is an important distinction between using genetic technologies to treat those who are suffering and to make those who are already healthy superior to the average. There is widespread agreement that germline engineering should not currently be allowed for either therapeutic and enhancement applications, as evidenced by a recent report by the American Association for the Advancement of Science. .Though theory and speculation suggest that genetic engineering could be used to make people stronger, faster, smarter, or to increase lung capacity, the AAAS report finds that there is little evidence that this can currently be done without very unsafe and therefore unethical human experiments. Because different cells have different tasks, changing one cell to do a different job will not only affect that one task, it can affect many others too
Multifactorial and polygenic disorders
Genetic disorders may also be complex, multifactorial or polygenic, this means that they are likely associated with the effects of multiple genes in combination with lifestyle and environmental factors. Multifactoral disorders include heart disease and diabetes. Although complex disorders often cluster in families, they do not have a clear-cut pattern of inheritance. This makes it difficult to determine a person’s risk of inheriting or passing on these disorders. Complex disorders are also difficult to study and treat because the specific factors that cause most of these disorders have not yet been identified.
On a pedigree, polygenic diseases do tend to “run in families”, but the inheritance does not fit simple patterns as with Mendelian diseases. But this does not mean that the genes cannot eventually be located and studied. There is also a strong environmental component to many of them (e.g., blood pressure).
autism
heart disease
hypertension
diabetes
obesity
cancers
cleft palate
Mental retardation
On a pedigree, polygenic diseases do tend to “run in families”, but the inheritance does not fit simple patterns as with Mendelian diseases. But this does not mean that the genes cannot eventually be located and studied. There is also a strong environmental component to many of them (e.g., blood pressure).
autism
heart disease
hypertension
diabetes
obesity
cancers
cleft palate
Mental retardation
X-linked dominant
X-linked dominant disorders are caused by mutations in genes on the X chromosome. Only a few disorders have this inheritance pattern. Males are more frequently affected than females, and the chance of passing on an X-linked dominant disorder differs between men and women. The sons of a man with an X-linked dominant disorder will not be affected, and his daughters will all inherit the condition. A woman with an X-linked dominant disorder has a 50% chance of having an affected daughter or son with each pregnancy. Some X-linked dominant conditions, such as Aicardi Syndrome, are fatal to boys, therefore only girls have them (and boys with Klinefelter Syndrome). Other examples of this type of disorder are Hypophosphatemia, Aicardi Syndrome, and Chokenflok Syndrome.
Autosomal recessive
Two copies of the gene must be mutated for a person to be affected by an autosomal recessive disorder. An affected person usually has unaffected parents who each carry a single copy of the mutated gene (and are referred to as carriers). Two unaffected people who each carry one copy of the mutated gene have a 25% chance with each pregnancy of having a child affected by the disorder. Examples of this type of disorder are Cystic fibrosis, Sickle cell anemia(Also Partial Sickle Cell Anemia), Tay-Sachs disease, Spinal muscular atrophy, and Dry (otherwise known as "rice-brand") earwax.
Autosomal dominant
Only one mutated copy of the gene will be necessary for a person to be affected by an autosomal dominant disorder. Each affected person usually has one affected parent. There is a 50% chance that a child will inherit the mutated gene. Conditions that are autosomal dominant have low penetrance, which means that, although only one mutated copy is needed, a relatively small proportion of those who inherit that mutation go on to develop the disease, often later in life. Examples of this type of disorder are Huntington's disease, Neurofibromatosis 1, Marfan Syndrome, Hereditary nonpolyposis colorectal cancer, and Hereditary multiple exostoses,which is a high penetrance autosomal dominant disorder
Single gene disorders
Where genetic disorders are the result of a single mutated gene they can be passed on to subsequent generations in the ways outlined in the table below. Genomic imprinting and uniparental disomy, however, may affect inheritance patterns. The divisions between recessive and dominant are not "hard and fast" although the divisions between autosomal and X-linked are (related to the position of the gene). For example, achondroplasia is typically considered a dominant disorder, but children with two genes for achondroplasia have a severe skeletal disorder that achondroplasics could be viewed as carriers of. Sickle-cell anemia is also considered a recessive condition, but carriers that have it by half along with the normal gene have increased immunity to malaria in early childhood, which could be described as a related dominant condition
Genetic disorder
A genetic disorder is a condition caused by abnormalities in genes or chromosomes. While some diseases, such as cancer, are due to genetic abnormalities acquired in a few cells during life, the term "genetic disease" most commonly refers to diseases present in all cells of the body and present since conception. Some genetic disorders are caused by chromosomal abnormalities due to errors in meiosis, the process which produces reproductive cells such as sperm and eggs. Examples include Down syndrome (extra chromosome 21), Turner Syndrome (45X0) and Klinefelter's syndrome (a male with 2 X chromosomes). Other genetic changes may occur during the production of germ cells by the parent. One example is the triplet expansion repeat mutations which can cause fragile X syndrome or Huntington's disease. Defective genes may also be inherited intact from the parents. In this case, the genetic disorder is known as a hereditary disease. This can often happen unexpectedly when two healthy carriers of a defective recessive gene reproduce, but can also happen when the defective gene is dominant.
Currently about 4,000 genetic disorders are known, with more being discovered. Most disorders are quite rare and affect one person in every several thousands or millions. Cystic fibrosis is one of the most common genetic disorders; around 5% of the population of the United States carry at least one copy of the defective gene. Some types of recessive gene disorder confer an advantage in the heterozygous state in certain environments.Genetic diseases are typically diagnosed and treated by geneticists. Genetic counselors assist the physicians and directly counsel patients. The study of genetic diseases is a scientific discipline whose theoretical underpinning is based on population genetics
Currently about 4,000 genetic disorders are known, with more being discovered. Most disorders are quite rare and affect one person in every several thousands or millions. Cystic fibrosis is one of the most common genetic disorders; around 5% of the population of the United States carry at least one copy of the defective gene. Some types of recessive gene disorder confer an advantage in the heterozygous state in certain environments.Genetic diseases are typically diagnosed and treated by geneticists. Genetic counselors assist the physicians and directly counsel patients. The study of genetic diseases is a scientific discipline whose theoretical underpinning is based on population genetics
When do Genetic Engineering make changes?
Changes at conception
Genetic engineering is most easily accomplished by making changes just after the egg and sperm have melded but before first division. In this way, the gene will be expressed throughout and will affect the recipients children, grandchildren, and all subsequent generations. Germline engineering is controversial because there is insufficient knowledge about DNA expression to accurately judge what result these changes will have.
Changes after birth
As of now, this is likely to take the form of gene therapy. This would not be hereditary unless the sex cells are engineered.
Genetic engineering is most easily accomplished by making changes just after the egg and sperm have melded but before first division. In this way, the gene will be expressed throughout and will affect the recipients children, grandchildren, and all subsequent generations. Germline engineering is controversial because there is insufficient knowledge about DNA expression to accurately judge what result these changes will have.
Changes after birth
As of now, this is likely to take the form of gene therapy. This would not be hereditary unless the sex cells are engineered.
Nanotechnology
Computers
The future most likely lies in a process that is automated by a wide repository of knowledge, a method of combining that knowledge into an embryo, and a design system such as a computer program that is easily represented to human individuals. The researcher is able to pick and choose what characteristics the "soon to be created human" should have, such as high intelligence, high strength, 20/20 or above vision, etc, and then tells the computer to create that person. This designer baby machine would then search through current research on these genes, put them into the proper places of the DNA mode through an accurate DNA modification method, enter it into an egg (created or taken from a female), and then insert the egg into a female or a mechanical womb.
Future technology
There are limitations to what current technology can do. Research scientists want to get finer control on how DNA sequences might be added to a host cell. Technologies that could offer this sort of control might well result from a merger of highly engineered/modified viruses with micromechanical technologies, modified to migrate to a particular specified N nucleotide sequence in the host DNA for N significantly large to minimize targeting errors, then precisely and efficiently insert the desired snippet in the correct position in the host. Evidently it would be desirable to allow such a device/organism to feed on available resources in the host in order to migrate from cell to cell and perform this process until a significant proportion of host cells had been transformed; it would then be desirable for the device to disable itself. Also it would be desirable for the device to understand when it had finished with a cell (e.g. after levels of a desired protein reach a critical threshold, though this would be perhaps too slow, i.e. movement via measurement of some sort of chemical gradient) so that it could move on. Certainly such devices could not be user controlled for a large population; they would need to be autonomous.
Since DNA sequences vary from individual to individual, and individuals may even be chimeras, also required would be the capability to sequence individual genomes, the ability to target fixes to particular parts of a chimera population, and finally a good understanding of how to avoid disruptive edits- that is, edits that do not disrupt the functioning of some other process in the cell. This requires some level of mastery of the area of proteomics, that is, the understanding of a lifeform's proteome.
Since DNA sequences vary from individual to individual, and individuals may even be chimeras, also required would be the capability to sequence individual genomes, the ability to target fixes to particular parts of a chimera population, and finally a good understanding of how to avoid disruptive edits- that is, edits that do not disrupt the functioning of some other process in the cell. This requires some level of mastery of the area of proteomics, that is, the understanding of a lifeform's proteome.
Current technology
One available method is gene manipulation through virus insertion. The main mechanism by which this operates is a fairly standard one; one is taking advantage of the way viruses hi-jack the cellular machinery to make multiple copies of themselves. The way they do this is by inserting a segment of their genome into the DNA of the host after penetrating the cellular wall, and so use this to instruct the host cell to produce multiple copies of the virus. This process could be utilized as a mechanism to spread new DNA by altering the genome of the virus itself to include the desired new DNA sequence. The altered virus could be injected into a host cell, where it would propagate and eventually spread the new DNA throughout the host’s body. Problems with this approach may be:
Randomness of the insertion of the DNA fragment wanted (this might lead, for instance, to a cell turning cancerous, or being more subtly disrupted),
Possible lack of control over the immune response to the "retrovirus", and
Possible problems getting complete transformation of the target cell population.
Another approach is to take advantage of the cell's endogenous ability to undergo homologous recombination wherein an exogenous DNA fragement with ends matching an endogenous gene replaces the target gene by action of enzymes called recombinases. This is the technology used for "knockouts" and "knock-ins" and generally cannot be performed on an intact organism and is therefore only a candidate for germline (i.e. single cell) genetic manipulation. This technology has very widespread usage in mouse genetics wherein genetically altered embryos are grown in a surrogate mother. This could easily be extended to humans in the very near future as there are no major additional technological hurdles remaining to engineer humans versus mice (though minor hurdles certainly remain). The primary hurdle is ethical, as the efficiency of this process can be quite poor and many embryos would be sacrificed in order to produce one genetically modified offspring.
Randomness of the insertion of the DNA fragment wanted (this might lead, for instance, to a cell turning cancerous, or being more subtly disrupted),
Possible lack of control over the immune response to the "retrovirus", and
Possible problems getting complete transformation of the target cell population.
Another approach is to take advantage of the cell's endogenous ability to undergo homologous recombination wherein an exogenous DNA fragement with ends matching an endogenous gene replaces the target gene by action of enzymes called recombinases. This is the technology used for "knockouts" and "knock-ins" and generally cannot be performed on an intact organism and is therefore only a candidate for germline (i.e. single cell) genetic manipulation. This technology has very widespread usage in mouse genetics wherein genetically altered embryos are grown in a surrogate mother. This could easily be extended to humans in the very near future as there are no major additional technological hurdles remaining to engineer humans versus mice (though minor hurdles certainly remain). The primary hurdle is ethical, as the efficiency of this process can be quite poor and many embryos would be sacrificed in order to produce one genetically modified offspring.
What kind of technology could be used for gene manipulation?
1.Current Technnology
2.Future Technology
3.Computers
4.Nanotechnology
2.Future Technology
3.Computers
4.Nanotechnology
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