Science & Technology - Genetics

 Science & Technology - Genetics

Genetics + Biotechnology

About

• Genetics is the study of heredity. Heredity is a biological process where a parent passes certain genes onto their children or offspring. Every child inherits genes from both of their biological parents and these genes, in turn, express specific traits. Some of these traits may be physical for example hair and eye color and skin color etc. On the other hand, some genes may also carry the risk of certain diseases and disorders that may pass on from parents to their offspring.
• The genetic information lies within the cell nucleus of each living cell in the body. The information can be considered to be retained in a book for example. Part of this book with the genetic information comes from the father while the other part comes from the mother.
• Genes generally express their functional effect through the production of proteins, which are complex molecules responsible for most functions in the cell. Proteins are made up of one or more polypeptide chains, each of which is composed of a sequence of amino acids, and the DNA sequence of a gene (through an RNA intermediate) is used to produce a specific amino acid sequence. This process begins with the production of an RNA molecule with a sequence matching the gene's DNA sequence, a process called transcription.

Chromosomes

• The genes lie within the chromosomes. Humans have 23 pairs of these small thread-like structures in the nucleus of their cells. 23 or half of the total 46 comes from the mother while the other 23 comes from the father.
• The chromosomes contain genes just like pages of a book. Some chromosomes may carry thousands of important genes while some may carry only a few. The chromosomes, and therefore the genes, are made up of the chemical substance called DNA (Deoxyribo Nucleic Acid). The chromosomes are very long thin strands of DNA, coiled up tightly.
• At one point along their length, each chromosome has a constriction, called the centromere. The centromere divides the chromosomes into two ‘arms’: a long arm and a short arm. Chromosomes are numbered from 1 to 22 and these are common for both sexes and called autosomes. Two chromosomes have been given the letters X and Y and termed sex chromosomes. The X chromosome is much larger than the Y chromosome.
• The genes are further made up of unique codes of chemical bases comprising of A, T, C and G (Adenine, Thymine, Cytosine, and Guanine). These chemical bases make up combinations with permutations and combinations. These are akin to the words on a page.
• These chemical bases are part of the DNA. The words when strung together act as the blueprints that tell the cells of the body when and how to grow, mature and perform various functions. With age, the genes may be affected and may develop faults and damages due to environmental and endogenous toxins.
• Women have 46 chromosomes (44 autosomes plus two copies of the X chromosome) in their body cells. They have half of this or 22 autosomes plus an X chromosome in their egg cells.
• Men have 46 chromosomes (44 autosomes plus an X and a Y chromosome) in their body cells and have half of these 22 autosomes plus an X or Y chromosome in their sperm cells.
• When the egg joins with the sperm, the resultant baby has 46 chromosomes (with either an XX in a female baby or XY in a male baby).

The work of Mendel

• Before Gregor Mendel, theories for a hereditary mechanism were based largely on logic and speculation, not on experimentation. In his monastery garden, Mendel carried out a large number of cross-pollination experiments between variants of the garden pea, which he obtained as pure-breeding lines. He crossed peas with yellow seeds to those with green seeds and observed that the progeny seeds were all yellow.
• Mendel also analyzed pure lines that differed in pairs of characters, such as seed color (yellow versus green) and seed shape (round versus wrinkled). The cross of yellow round seeds with green wrinkled seeds resulted in the generation of yellow and round seeds, revealing the dominance of the yellow and round traits.

Genes and genetics

• Each gene is a piece of genetic information. All the DNA in the cell makes up for the human genome. There are about 20,000 genes located on one of the 23 chromosome pairs found in the nucleus.
• To date, about 12,800 genes have been mapped to specific locations (loci) on each of the chromosomes. This database was begun as part of the Human Genome Project. The project was officially completed in April 2003 but the exact number of genes in the human genome is still unknown.

Genome Sequencing

• Genome is an organism’s complete set of DNA, including all of its genes.
  • Each genome contains all of the information needed to build and maintain that organism. In humans, a copy of the entire genome—more than 3 billion DNA base pairs—is contained in all cells that have a nucleus.
• It is figuring out the order of DNA nucleotides, or bases, in a genome—the order of As, Cs, Gs, and Ts that make up an organism's DNA. The human genome is made up of over 3 billion of these genetic letters.
• Sequencing the genome doesn't immediately lay open the genetic information of an entire species. Even with a rough draft of the human genome sequence in hand, much work remains to be done. Scientists still have to translate those strings of letters into an understanding of how the genome works.

Genome editing

• Genome editing/gene editing is a group of technologies that give scientists the ability to change an organism's DNA. These technologies allow genetic material to be added, removed, or altered at particular locations in the genome.
• Several approaches to genome editing have been developed. A recent one is known as CRISPR-Cas9, which is short for Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR-associated protein 9.
• The CRISPR-Cas9 system is faster, cheaper, more accurate, and more efficient than other existing genome editing methods.

CRISPR-Cas9

• It is a unique technology that enables geneticists and medical researchers to edit parts of the genome by removing, adding or altering sections of the DNA sequence.
• CRISPRs are specialized stretches of DNA. The protein Cas9(or "CRISPR-associated") is an enzyme that acts like a pair of molecular scissors, capable of cutting strands of DNA. It allows researchers to easily alter DNA sequences and modify gene function.
• It is the simplest yet powerful tool for editing genomes and also termed as the most versatile and precise method of genetic manipulation.

Biotechnology

About

• Biotechnology is defined as the industrial application of living organisms and their biological processes such as biochemistry, microbiology, and genetic engineering, to make the best use of the microorganisms for the benefit of mankind.
• Different types of biotechnology
  • Green biotechnology: Green biotechnology is defined as the application of biological techniques to plants to improve the nutritional quality, quantity and production economics. It is done by implanting foreign genes to plant economically important species. This contains three main areas: plant tissue culture; plant genetic engineering and plant molecular marker-assisted breeding.
  • Red biotechnology: Red biotechnology is concerned with the discovery and development of innovative drugs and treatments. A key prerequisite was an increasing understanding of how proteins function, their roles in communication between and within cells, and the diseases caused when these proteins malfunction.  This includes Gene Therapy, Stem Cells, Genetic Testing, etc.
  • White biotechnology: This field of biotechnology is connected with the industry. White biotech uses molds, yeasts, bacteria, and enzymes to produce goods and services or parts of products. It offers a wide range of bio-products like detergents, vitamins, antibiotics, etc. Most of the white biotech processes result in the saving of water, energy, chemicals and the reduction of waste compared to traditional methods.
  • Blue biotechnology: Blue biotechnology is concerned with the application of molecular biological methods to marine and freshwater organisms. It involves the use of these organisms, and their derivatives, for multiple purposes, the most remarkable are the identification process and development of new active ingredients from marine origin.
  • Yellow biotechnology: Yellow biotechnology’ refers to biotechnology with insects — analogous to the green (plants) and red (animals) biotechnology. Active ingredients or genes in insects are characterized and used for research or application in agriculture and medicine.

Applications

• Biopharmaceuticals: The drugs are being developed with the use of microorganisms without using any synthetic materials and chemicals. Large molecules of proteins are usually the source of biopharmaceutical drugs. They when targeted in the body attack the hidden mechanisms of the diseases and destroy them without any side effect(s). Now scientists are trying to develop such biopharmaceutical drugs that can be treated against diseases like hepatitis, cancer and heart diseases.
• Gene therapy: It is used in delicacy and diagnoses of diseases like cancer and Parkinson’s. The apparatus of this technique is that the fit genes are under attack in the body which either obliterate the injured cells or replace them. In some cases, the fit genes make corrections in the genetic information and that is how the genes start performance in the favor of the body.
• Flowers: There is extra to agricultural biotechnology than just hostility disease or civilizing food quality. There is some simply aesthetic application and an example of this is the use of gene recognition and transfer techniques to improve the color, smell, size and other features of flowers.
• Plant and Animal Reproduction: Enhancing plant and animal behavior by traditional methods like cross-pollination, grafting, and cross-breeding is time-consuming. Biotech advance let for specific changes to be made rapidly, on a molecular level through over-expression or removal of genes, or the introduction of foreign genes.
• Food processing is a process by which non-palatable and easily perishable raw materials are converted to edible and potable foods and beverages, which have a longer shelf life. The method, by which the microbial organisms and their derivatives are used to increase the edibility and the shelf life of foods, is known as fermentation.
• Bioremediation: The process of cleaning up the hazardous substances into non-toxic compounds is called the Bioremediation process. This process is majorly used for any kind of technology clean up that uses the natural microorganisms.

Biotechnology Projects

Human Genome Project

• The "genome" of any given individual is unique; mapping the "human genome" involved sequencing a small number of individuals and then assembling these to get a complete sequence for each chromosome. The finished human genome is thus a mosaic, not representing any one individual.
• The Human Genome Project (HGP) was an international scientific research project.
• It can help us understand diseases including: genotyping of specific viruses to direct appropriate treatment.
• Identification of mutations linked to different forms of cancer.
• The design of medication and a more accurate prediction of their effects.
• Advancement in forensic applied sciences.
• Biofuels and other energy applications.
• Agriculture, animal husbandry, bioprocessing; risk assessment; bioarchaeology, anthropology, and evolution.
• Commercial development of genomics research related to DNA based products, a multibillion-dollar industry.

Gene editing:

• This is a technique that allows the scientist to edit the gene sequence and then modify it to bring the desired changes. It helps to understand the sequence of genes and then use gene editing to cure incurable diseases like Tay-Sachs and perhaps cystic fibrosis through the modification of genes.
• In addition to that, gene editing can be used as a research tool to simply learn more about these diseases.

GM Mustard Issue

• DMH-11 is a Genetically Modified (GM) mustard hybrid. Hybrids are normally obtained by crossing 2 genetically diverse plants from the same species. The 1st-generation offspring resulting from it has higher yields than what either of the parents is individually capable of giving.
• But there is no natural hybridization system in mustard, unlike in, say, cotton, maize or tomato. This is because its flowers contain both the female (pistil) and male (stamen) reproductive organs, making the plant naturally self-pollinating. What scientist has done is to create a viable hybridization system in mustard using GM technology. The resulting GM mustard hybrid, it is claimed, gives 25-30% more yield than the best varieties such as 'Varuna' currently grown in the country.
• Scientists at the Centre for Genetic Manipulation of Crop Plants (CGMCP) in Delhi University, however, showed that this problem could be addressed by crossing Indian mustard cultivars with juncea lines of East European origin like 'Early Heera' and 'Donskaja'. The combination of the 2 divergent gene pools enhanced the crossing options; the resultant F1 progeny were found to exhibit significant heterosis.

Terminologies associated with the biotechnology

• Cell: The cell is the basic structure of the body. The human body is built of billions and trillions of cells. Each cell contains the hereditary material and can make copies of themselves by reproducing and multiplying. After a specific life span, the old cells die off. Parts of the cell are called organelles.
• DNA: Deoxyribonucleic acid (DNA) is a molecule that encodes the genetic instructions used in the development and functioning of all known living organisms.
• GENE: A gene is a segment of nucleic acid that contains the information necessary to produce a functional product, usually a protein. The genes are made up of a coding alphabet of 4 nucleotides made up of 4 bases:- Adenine (A), Thymine (T), Guanine (G) and Cytosine (C) present in DNA.
• Genetic engineering: Techniques to alter the chemistry of genetic material (DNA and RNA), to introduce these into host organisms and thus change the phenotype of the host organism.
• Gene Therapy: This is in a way, genetic engineering of humans, which would allow a person suffering from a disabling genetic disorder to lead a normal life.
• Genome Resource Bank: Genome Resource Bank (GRB) is a frozen repository of biological materials, including sperm and embryos, tissue, blood products, and DNA. It is going to being used as a conservation tool for protecting and preserving biodiversity.
• Human Genome Project: The Human Genome Project aimed to identify all the genes (approx. 25,000) in human DNA and to determine the sequence of the three billion chemical base pairs that make up human DNA. Efforts were made to create databases to store this information and develop tools to do comprehensive data analysis.
• Bioinformatics: Bioinformatics is an independent discipline that merges the field of molecular biology and computer science. This mainly involves the transformation of biological polymers such as nucleic acid molecules and proteins into sequences of digital symbols. The symbols and their meaning for the protein sequences have also been generated.
• Bioremediation: Bioremediation is the use of microorganisms for the degradation of hazardous chemicals in soil, sediments, water, or other contaminated materials. It uses naturally occurring bacteria and fungi or plants to degrade or detoxify substances hazardous to human health and/or the environment.
• Biosensors: Biosensors are biophysical devices that can detect the presence of specific substancesg. sugars, proteins, hormones, pollutants and a variety of toxins in the environment.
• Bioreactors: Bioreactors can be thought of as vessels in which raw materials are biologically converted into specific products, individual enzymes, etc., using microbial plant, animal or human cells.
• Bioprospecting is an umbrella term describing the process of discovery and commercialization of new products based on biological resources, typically in less-developed countries. Bioprospecting often draws on indigenous knowledge about the uses and characteristics of plants and animals. In this way, bioprospecting includes biopiracy, the exploitative appropriation of indigenous forms of knowledge by commercial actors, as well as the search for previously unknown compounds in organisms that have never been used in traditional medicine.
• Biopiracy is a situation where indigenous knowledge of nature, originating with indigenous people, is used by others for profit, without permission from and with little or no compensation or recognition to the indigenous people themselves.
• Green consumerism refers to recycling, purchasing and using eco-friendly products that minimize damage to the environment. This involves decisions such as using Energy Start appliances that consume less power, buying hybrid cars that emit less carbon dioxide, using solar and wind power to generate electricity and buying locally grown vegetables and fruits.
• A Comprehensive Environmental Pollution Index (CEPI)is a very useful tool to capture the health dimensions of the environment including air, water, and land. The CEPI is intended to act as an early warning tool and can help in categorizing the industrial clusters/areas in terms of priority of planning needs for interventions.
• Bioregionalism is a political, cultural, and ecological system or set of views based on naturally defined areas called bioregions, similar to ecoregions. Bioregions are defined through physical and environmental features, including watershed boundaries and soil and terrain characteristics. Bioregionalism stresses that the determination of a bioregion is also a cultural phenomenon, and emphasizes local populations, knowledge, and solutions.
• Bioethics: Bioethics is the branch of ethics, philosophy, and social commentary that deals with the biological sciences and its impact on society.
• Vaccine: A preparation that contains an agent or its components, administered to stimulate an immune response that will protect a person from illness due to that agent. A therapeutic (treatment) vaccine is given after the disease has started and is intended to reduce or arrest the progress of the disease. A preventive (prophylactic) vaccine is intended to prevent the disease from starting. Agents used in vaccines may be whole-killed (inactive), live-attenuated (weakened) or artificially manufactured. It can be created using the recombinant DNA process.
• Vector: A vehicle that carries foreign genes into an organism and inserts them into the organism’s genome. Modified viruses are used as vectors for gene therapy.
• Virus:A submicroscopic particle that can infect other organisms. It cannot reproduce on its own but infects an organism’s cell to use that cell’s reproductive machinery to create more viruses. It usually consists of a DNA or RNA genome enclosed in a protective protein coat.
• Stem cell: A fundamental cell that has the potential to develop into any of the 210 different cell types found in the human body. Human life begins with stem cells, which divide again and again and branch off into special roles, like becoming liver or heart cells. They are an important resource for disease research and for the development of new ways to treat disease.
• Amniocentesis: A procedure used in prenatal diagnosis to look at the chromosomes of the developing fetus. A flexible needle is inserted into the mother’s uterus through the abdomen to remove a sample of the fluid surrounding the fetus (amniotic fluid). This sample can then be analyzed by karyotype to look for changes in the chromosomes. The procedure can be done after 15 weeks of pregnancy. There is a 0.5% risk of miscarriage associated with this procedure, which means one in 200 women will miscarry following this procedure.
• Embryonic stem cells: Cells that are removed from the early embryo and can become any of the 210 cell types found in the human body. Researchers are looking at the great potential stem cells have in developing new treatments for disease and injury.