S7 2p Genetic Manipulation PDF

S7 2p Topic 1: Genetic manipulation Genetics basic notions [reminder] The DNA molecule is made of 2 chains organized in a double helix with planar structures in between called nucleotides (A, T, C & G). A hy...

S7 2p Topic 1: Genetic manipulation Genetics basic notions [reminder] The DNA molecule is made of 2 chains organized in a double helix with planar structures in between called nucleotides (A, T, C & G). A hydrogen bond in between 2 nitrogenous bases can only form in between specific nucleotides. Because of chemical properties, A can only bind to T, forming 2 hydrogen bonds, and C can only bind to G, forming 3 hydrogen bonds. The molecule of DNA is universal, but each species possesses a sequence that have a specific length and sequence of nucleotides that, for example, determine which organelle is present inside a cell. The whole DNA sequence contained inside a cell is called the genome. As the genome may be incredibly long, it may be broken down into several long molecules of DNA called chromosomes. Chromosomes are unravelled and not visible during most of the cell life. However, during mitosis or meiosis they condense forming a visible rod-structure. Although the whole human population share about 99,9% of their genome, we still have a certain number of genetic differences. When we look at a gene (=nucleotide sequence that can lead to the production of an entire protein) sequence, we can see some difference in the nucleotide sequence. In the diagram below, the 120 nucleotide is different for those 4 individuals. Those different variation of a gene are called alleles. Depending on the genetic code, they can lead to a different protein or not. If the amino acid sequence is different, the function of the protein will be different too, leading to an increased or decrease efficiency of its function.  S7 2p Topic 1: Genetic manipulation Variability among a population can be given by mutations. Those mutations happen either spontaneously during DNA replication or during DNA repair, whenever some damages happen to the DNA sequence due to environmental factors or chemicals.  S7 2p Topic 1: Genetic manipulation Context of genetic manipulations In this chapter, we’ll survey the practical applications of DNA-based biotechnology, the manipulation of organisms or their components to make useful products. Today, major applications of DNA technology and genetic engineering include medicine, forensic evidence and genetic profiles, environmental cleanup, and agriculture. Medical Applications One important use of DNA technology is the identification of human genes whose mutation plays a role in genetic diseases. These discoveries may lead to ways of diagnosing, treating, and even preventing such conditions. DNA technology has also identified genes that play a role in a number of “nongenetic” diseases, from arthritis to AIDS, by influencing susceptibility to these diseases. Furthermore, a wide variety of diseases involve changes in gene expression within the affected cells and often within the patient’s immune system. Genetic manipulation can be used in the medical context in a number of ways, including: Gene therapy: a technique that involves replacing or modifying a gene to treat a disease. Gene therapy can be used to treat a variety of genetic disorders, such as cystic fibrosis and sickle cell anemia. It can also be used to treat some cancers. Genetic testing: it can be used to identify people who are at risk for developing certain genetic disorders. This information can be used to develop preventive measures or to make informed decisions about reproductive planning. Prenatal genetic testing can be used to identify genetic disorders in a fetus before birth. This information can be used to make informed decisions about pregnancy and childbirth. Personalized medicine: Personalized medicine is an approach to medicine that takes into account a person's individual genetic makeup. This information can be used to develop more effective and targeted treatments for diseases. Here are some specific examples of how genetic manipulation is being used in the medical context today: CRISPR-Cas9 gene editing: CRISPR-Cas9 is a powerful gene editing tool that can be used to make precise changes to DNA. CRISPR-Cas9 is being used in research to develop new gene therapies for a variety of diseases, including cancer, HIV/AIDS, and sickle cell anemia. CAR T-cell therapy: CAR T-cell therapy is a type of gene therapy that involves engineering a patient's own immune cells to recognize and attack cancer cells. CAR T-cell therapy has been shown to be very effective in treating certain types of leukemia and lymphoma. Genetic manipulation is a rapidly developing field with the potential to revolutionize medicine. As we learn more about our genes and how to manipulate them, we will be able to develop new treatments for a wide range of diseases.  S7 2p Topic 1: Genetic manipulation Agricultural Applications Genetic manipulation can be used in the agricultural context in a number of ways, including: Developing crops with improved yields: Genes can be inserted into crops to improve their yields, making them more productive and resistant to pests and diseases. For example, genetically modified (GM) crops have been developed that are resistant to herbicides and insects. This allows farmers to use fewer pesticides and herbicides, which can reduce costs and environmental impact. Developing crops with improved nutritional value: Genes can also be inserted into crops to improve their nutritional value. For example, GM crops have been developed that are high in vitamins and minerals, such as beta-carotene and iron. This can help to improve the nutritional status of people who consume these crops. Developing crops with improved tolerance to abiotic stresses: Genes can also be inserted into crops to improve their tolerance to abiotic stresses, such as drought, salinity, and cold. This can help to expand the range of areas where crops can be grown and improve their resilience to climate change. Here are some specific examples of how genetic manipulation is being used in the agricultural context today: Bt corn: Bt corn is a type of GM corn that produces a protein that is toxic to certain insects. This allows farmers to reduce their use of insecticides. Golden Rice: Golden Rice is a type of GM rice that has been engineered to produce beta-carotene, a precursor to vitamin A. This can help to reduce vitamin A deficiency, which is a major public health problem in developing countries. Drought-tolerant soybeans: Drought-tolerant soybeans are a type of GM soybean that has been engineered to be more tolerant of drought stress. This can help farmers to grow soybeans in areas that are prone to drought. Genetic manipulation has the potential to revolutionize agriculture. By developing crops with improved yields, nutritional value, and tolerance to abiotic stresses, we can help to feed a growing population and reduce our environmental impact. However, there are a number of concerns regarding genetically modified organisms: Health and environmental risks: Some people are concerned about the potential health risks of eating GMOs. These concerns include the possibility that GMOs could cause allergies, new diseases, or antibiotic resistance. Concerns regarding environmental risks include the possibility that GMOs could cross-pollinate with wild plants, creating new weeds or superweeds. There is also concern that GMOs could harm beneficial insects, such as butterflies and bees. However, there is no scientific evidence to support these claims. GMOs have been extensively tested and found to be safe for human consumption and no environmental impact have been observed until now. Corporate control: Some people are concerned about the corporate control of the GMO industry. A small number of multinational companies control the vast majority of the global GMO market. This raises concerns about the potential for these companies to monopolize the food supply and control food prices. Ethical concerns: Some people have ethical concerns about GMOs. For example, some people believe that it is wrong to modify the genes of living organisms. Others believe that it is wrong to patent seeds and other genetic resources.  S7 2p Topic 1: Genetic manipulation Despite these concerns, GMOs are widely used in agriculture today. GMO crops are grown in over 26 countries around the world, and they account for over a quarter of the global cropland. GMOs have helped to increase crop yields and reduce pesticide use. They have also been used to develop crops that are resistant to pests and diseases. Other scientific contexts To study gene function: Genetic manipulation can be used in labs to identify and study the function of specific genes. Cells can be engineered with genes that are “switched-off” or with genes that are “switched on”. By modifying their expression, scientists can learn more about how they work and what roles they play in different biological processes. To model diseases: Genetic manipulation can be used to create animal models of human diseases. This can be done by inserting genes that cause human diseases into animals. By studying animal models of disease, scientists can learn more about the causes and progression of diseases, and develop new treatments and diagnostic tests. To develop new therapies: Genetic manipulation is also being used to develop new drugs and vaccines. To produce protein with genetically modified bacteria: Genetically modified bacteria are being used to produce a variety of useful products, such as insulin, vaccines, and biofuels. Stem cells research Stem cell overview (in complement with the “stem cell basics” sheet given in class) Stem cells are undifferentiated cells that have the potential to develop into different types of cells in the body. They are the building blocks of all life and are essential for growth, repair, and regeneration. There are two main types of stem cells: embryonic stem cells and adult stem cells. Embryonic stem cells are derived from early-stage embryos. Adult stem cells are found in various tissues throughout the body, such as bone marrow, blood, and fat. Applications of Stem Cell Research Stem cell research is a rapidly growing field with the potential to revolutionize medicine. Stem cells can be used to treat a variety of diseases, including cancer, blood disorders, and autoimmune diseases. They can also be used to repair damaged tissues and organs. Stem cell research has the potential to be used in a wide range of medical applications, including: Cancer treatment: Stem cells can be used to develop new cancer treatments, such as personalized cancer vaccines and targeted therapies. Blood disorders: Stem cells can be used to treat blood disorders, such as leukemia and lymphoma, by replacing damaged or diseased blood cells. Autoimmune diseases: Stem cells can be used to treat autoimmune diseases, such as multiple sclerosis and type 1 diabetes, by repairing damaged tissues and organs. Tissue and organ repair: Stem cells can be used to repair damaged tissues and organs, such as the heart, liver, and brain.  S7 2p Topic 1: Genetic manipulation Regenerative medicine: Stem cells can be used to regenerate damaged or diseased tissues and organs, such as the skin, bone, and cartilage. Challenges and Ethical Considerations Despite the potential of stem cell research, there are still a number of challenges that need to be addressed before stem cell therapies can be widely used. One challenge is that stem cell therapies can be complex and expensive. Another challenge is that there is a risk of side effects, such as the development of tumors. There are also a number of ethical considerations surrounding stem cell research. For example, some people believe that it is unethical to use embryonic stem cells for research because they are derived from human embryos. Potential consequences of genetic manipulations Genetic manipulation of humans has the potential to have a wide range of consequences, both positive and negative. In a non-exhaustive way, here is a list summarising how genetic manipulation can have a positive impact on the human society: Curing diseases: Genetic manipulation could be used to cure a wide range of diseases, including cancer, genetic disorders, and infectious diseases. Enhancing human abilities: Genetic manipulation could be used to enhance human abilities, such as intelligence, strength, and endurance. Prolonging human life: Genetic manipulation could be used to prolong human life by repairing damaged DNA and slowing down the aging process. However, there are also many ethical concerns about genetic manipulation. This technology needs indeed to be regulated as its use could have a large and uncontrolled impact on our society. Some fear that a eugenic debate (eugenic is a set of beliefs and practices that aim to improve the genetic quality of a human population – popularized by Nazi politics aiming at exterminating people judged genetically inferior) will be brought back from the past. Here is a non-exhaustive list of concerns regarding genetic manipulation. Unintended consequences: Genetic manipulation is a complex process, and there is a risk of unintended consequences. For example, a gene that is intended to cure one disease could cause another disease. Social inequality: Genetic manipulation could lead to increased social inequality, as people with access to genetic manipulation technologies could gain an advantage over those who do not. Genetically modified people would be resistant to certain diseases or would have a longer lifespan, leading to a world where people are divided into two classes: those who have been genetically modified and those who have not. Designer babies: Children could be designed to have specific traits, such as intelligence, athletic ability, or physical appearance. This could lead to a society where people are divided into different classes based on their genetic traits. Animal-Human hybrids: Genetic manipulation could be used to create new forms of life, such as human-animal hybrids. This could have unintended consequences for the environment and human society. Super soldiers: Genetic manipulation could be used to create "super soldiers" or other enhanced humans. This could lead to a more militaristic world.