BIOTECHNOLOGY

BIOTECHNOLOGY

Biotechnology is the use of biological systems found in organisms or the use of the living organisms themselves to make technological advances and adapt those technologies to various fields.

 

Colour Classification of Branches of Biotechnology:

  • Gold biotechnology or Bioinformatics: Computational Biology à address biological problems using computational techniques.
  • Red Biotechnology: Biopharma à relates to medicine and veterinary products.
  • White Biotechnology: Industrial Biotech à to design more energy efficient, low resource consuming products.
  • Yellow Biotechnology: Biotech in Food Industry.
  • Grey Biotechnology: Environmental applications to maintain Biodiversity.
  • Green Biotechnology: Emphasizes on Agriculture interests.
  • Blue Biotechnology: based on use of marine resources.
  • Violet Biotechnology: deals with law, ethical and philosophical issues of biotechnology.
  • Dark Biotechnology: associated with bioterrorism and biological weapons.

 

GENE:

  • Gene is the basic physical unit of inheritance.
  • It is a part of the DNA in a cell that controls the physical development, behaviour, etc. of an individual plant or animal & is passed on from its parents.

 

GENOME:

  • Genome is the complete set of genes or genetic material present in a cell or organisms.
  • The human genome is a complex set of instructions, like a recipe book, directing organism growth & development.

 

GENOMIC ORGANIZATION:

  • This refers to the linear order of DNA elements and their division into chromosomes.
  • Can also refer to the 3D structureof chromosomes & the positioning of DNA sequences within the nucleus.

 

CHROMOSOME:

  • Theseare thread-like structures located inside the nucleus of animal & plant cells.
  • Each chromosomeis made of protein and a single molecule of Deoxyribose-Nucleic Acid (DNA).
  • Chromosomes are a key part of the process that ensures DNA is accurately copied and distributed in the vast majority of cell divisions.
  • Changes in the number or structure of chromosomes in new cells may lead to serious problems like: Down Syndrome, Turner Syndrome etc.

 

DEOXYRIBONUCLEIC ACID (DNA):

  • DNA is an organic chemical that contains genetic information and instructions for protein synthesis.
  • DNAis a key part of reproduction in which genetic heredity passed down through DNA from parents to offspring.

 

RIBONUCLEIC ACID (RNA):

  • RNA is a nucleic acid principally involved in the synthesis of proteins, carrying the messenger (ex: mRNA) instructions from DNA, which itself contains the genetic instruction

 

DIFFERENCES BETWEEN DNA AND RNA:

DNA RNA
It has deoxyribose and phosphate backbone having four distinct bases: Adenine, Cytosine, Guanine & Thymine (ACGT). It has ribose and phosphate backbone with four bases: Adenine, Cytosine, Guanine& Uracil (ACGU).
Found in cell nucleus and Mitochondria. Found in Cytoplasm, nucleus and Ribosome.
Has 2-deoxyribose. Has Ribose.
Double stranded molecule with long chain of nucleotides. Single stranded molecule with shorter chain of nucleotides.
Self-replicating Synthesize from DNA when required.

 

CELL

  • A Cell is defined as smallest, basic unit of life responsible for all life’s processes.
  • Robert Hooke coined the term Cell in 1665.
  • Cells provide structure and support to the body of an organism.
  • Cells are of 2 types namely, Prokaryotes & Eukaryotes.

 

Prokaryotes Eukaryotes
Size of cell is generally small Size of cell is generally large.
Nucleus absent. Nucleus present.
It contains single chromosome It contains more than one chromosome
Membrane bound cell organelles are absent. Cell organelles are present.
Cell division takes place by fission or budding. Cell division takes place by mitosis and meiosis.

 

STRUCTURE OF A CELL

A cell consists of three parts:

  1. The cell membrane
  2. The nucleus, and, between the two,
  3. The cytoplasm.

 

 

 

The Cell membrane

 

·         Every cell in the body is enclosed by a cell (Plasma) membrane.

·         It maintains the integrity of a cell and controls passage of materials into and out of the cell.

·         All materials within a cell must have access to the cell membrane for the needed exchange.

 

 

The Nucleus & nucleolus

 

·         The nucleus determines how the cell will function, as well as the basic structure of that cell.

·         Threads of chromatin in the nucleus contain Deoxyribonucleic Acid (DNA), the genetic material of the cell.

·         The nucleolus is a dense region of ribonucleic acid (RNA) in the nucleus and is the site of ribosome formation.

The cytoplasm

 

·         Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane.

·         Within the cytoplasm lie intricate arrangements of fine fibers and hundreds or even thousands of miniscule but distinct structures called organelles.

·         Each type of organelle has a definite structure and a specific role in the function of the cell.

 

Organelle and its Function:

Organelle Function
Nucleus DNA Storage
Mitochondrion (Power house) Energy production
Smooth Endoplasmic Reticulum(SER) Lipid Production; Detoxification
Rough Endoplasmic Reticulum(RER) Protein production
Golgi apparatus (Cell’s Post office) Made of tubes, vesicles & vacuoles. Protein Modification and material transfer, also involved in the synthesis of Cell wall, Plasma membrane & Lysosomes
Peroxisome Lipid Destruction; contains oxidative enzymes
Lysosome (cell’s suicide bags) Protein Destruction
Chromosomes Determine the sex of an individual
Ribosome Protein synthesis
Chloroplast (Kitchen of the plant cell) It contains the pigment Chlorophyll–take part in Photosynthesis
Vacuole It helps in Osmoregulation. It stores toxic metabolic waste.

 

NOTE: Organelles are found only in plant cells.

 

PLASTID:

  • Plastid is a double membrane-bound organelle involved in the synthesis and storage of food.
  • Commonly found within the cells of photosynthetic plants.
  • It is of 3 types: Chloroplasts, Chromoplast & Leucoplast.
  • Chloroplasts: These are green pigments found in green plant involve in photosynthesis.
  • Chromoplast provides various colors to the plant like flower, fruit etc. For example, Carotene provide orange color for Carrot & Lycopene in tomato provide red color.
  • Leucoplast is colorless. It stores the food in the form of starch, fat & protein.

 

NOTE: Plastids were discovered and named by Ernst Haeckel, but A. F. W. Schimper was the first to provide a clear definition.

 

CELL WALL:

  • A cell wall is an outer layer surrounding certain cells that is outside of the cell membrane.
  • All cells have cell membranes, but generally only plants, fungi, algae, most bacteria, and archaea have cells with cell wall
  • The cell wall provides strength and structural support to the cell.

 

NOTE: Chitin a polysaccharide that is a main component of fungal cell walls and also of the exoskeletons of certain animals like insects.

 

DIFFERENCE BETWEEN PLANT AND ANIMAL CELL:

 

Plant Cell Animal Cell
Cell are larger in size Generally smaller
Cell wall – Present. Made up of Cellulose & Chitin Cell wall – Absent
Plastid present Plastid absent
Centrosome absent Centrosome present
Vacuole are larger in size Vacuole are smaller in size

 

STEM CELLS:

  • The smallest functional unit of life is called the Cell.
  • These cells develop to form tissues which in turn develop to form organs.
  • Stem cells are basically undifferentiated, primitive cells which have the potential to develop into many different types of cells like those in muscles, kidney, liver etc.
  • Stem cell therapy has shown potential to cure many severe ailments. It is touted as future of medical treatments.
  • They have proved effective in the treatment of blood disorders, immune disorders, metabolic problems, & other organ degenerated diseases.

 

Growing Human Organs in Animal Body:

Recently Japanese researchers have successfully developed functional mouse kidneys inside rats using stem cells. This could be replicated in Humans.

 

Source of Stem Cells:

  • Bone marrow, Umbilical cord blood, Adipose tissue, Allografts, Amniotic fluid etc.
  • Based on Source: Types of stem Cells:
    1. Embryonic Stem Cells (ESCs)
    2. Adult/Somatic stem cells

Adult stem cells include:

  • Hematopoietic Stem cells (HSCs), Mesenchymal Stem Cells, Neural stem cells, Epithelial Stem cells, Skin stem cells, Induced pluripotent stem cells.
  • Induced pluripotent stem cells (iPS): Scientists create these in a lab, using skin cells and other tissue-specific cells. These cells behave in a similar way to embryonic stem cells, so they could be useful for developing a range of therapies.
  • These cells derived from the patient themselves, so less likely to be rejected.

 

Cell Potency:

  • Refers to the varying ability of stem cells to differentiate into specialized cell types.
  • Cells with greatest potency can generate more cells types than lower potency cell.

 

Hierarchy of Cell Potency:

  • Totipotent Stem Cells: Stem cells can give rise to any of 220 cell types found in embryo as well as extra-embryonic cells(placenta).
  • Pluripotent Stem Cells: can give rise to all cell types of body (but not the placenta).
  • Multipotent Stem Cells: can develop limited number of cell types in a particular lineage.
  • Unipotent Stem Cells: give rise to cells of their own type along a single lineage.

 

DNA Profiling:

  • DNA profiling is the process where a specific DNA pattern, called a profile, is obtained from a person or sample of bodily tissue.
  • It is a forensic technique in criminal investigations, comparing criminal suspects’ profiles to DNAevidence so as to assess the likelihood of their involvement in the crime.
  • It is also used in parentage testing, to establish immigration eligibility, and in genealogical and medical research.

 

Short Tandem Repeats (STRs):

  • One of the current techniques for DNA profiling uses polymorphisms called STRs.
  • These are regions of non-coding DNA that contain repeats of the same nucleotide sequence. Ex: GATAGATA

 

Genetic Disorders

  • A genetic disorder is a disease that is caused by a change, or mutation, in an individual’s DNA sequence.
  • These mutations can be due to an error in DNA replication or due to environmental factors, such as cigarette smoke & exposure to radiation, which cause changes in the DNA sequence.
  • The three main categories are:
    1. Single gene disorders:disorders caused by defects in one particular gene, often with simple and predictable inheritance patterns. Ex: Huntington’s disease, Cystic fibrosis.
    2. Chromosome disorders:disorders resulting from changes in the number or structure of the chromosomes. Ex: Down’s syndrome, which results from an extra chromosome 21.
    3. Multifactorial disorders (complex diseases):disorders caused by changes in multiple genes, often in a complex interaction with environmental & lifestyle factors such as diet or cigarette smoke. Ex:

 

Gene Therapy 

  • Technique to replace defective genes with healthy genes to treat genetic disorders.
  • Artificial method that introduces DNA into the cells of human body.
  • First developed in 1972, but has limited success.
  • Two types of gene therapy: Somatic gene therapy, Germline gene therapy.

 

Gene Editing:

  • Gene editing is a technique of making specific changes to the DNA at a specific sequence.
  • For this DNA is inserted, deleted, modified or replaced in the genome.
  • For this CRISPR CAS9 Scissor is used.
  • It involves making cuts at specific DNA sequences with enzymes called ‘engineered nucleases’.

 

How does genome edit work?

  • Genome editing uses a type of enzyme called an ‘engineered nuclease’ which cuts the genome in a specific place.
  • Engineered nucleases are made up of two parts:
    1. A nuclease part that cuts the DNA.
    2. A DNA-targeting part that is designed to guide the nuclease to a specific sequence of DNA.
  • After cutting the DNA in a specific place, the cell will naturally repair the cut. We can manipulate this repair process to make changes (or ‘edits’) to the DNA in that location in the genome.

 

 

CRISPR-Cas9:

  • CRISPR stands for ‘Clustered Regularly Interspaced Short Palindromic Repeats’
  • It is the most common, cheap & efficient system used for genome editing.
  • CRISPR is the DNA-targeting part of the system which consists of an RNAmolecule, or ‘guide’, designed to bind to specific DNA bases through complementary base-pairing.
  • Cas9 stands for CRISPR- associated protein 9, & is the nuclease part that cuts the DNA.
  • The CRISPR-Cas9 system was originally discovered in Bacteria that use this system to destroy invading

 

Zinc-Finger Nucleases (ZFN):

The DNA-binding part of ZFNs is made of zinc-finger proteins, which each bind to about three DNA bases. Different combinations of zinc-finger proteins bind to different sequences of DNA.

The nuclease part of ZFNs is normally a FokI nuclease, which cuts the DNA.

 

Gene Silencing

 

·         Gene silencing is the regulation of gene expression in a cell to prevent the expression of a certain gene.

·         When genes are silenced, their expression is reduced. Ex: the researchers designed two small RNA molecules that silence the fungal genes which produce aflatoxin in Groundnut.

·         When genes are knocked out, they are completely erased from the organism’s genome and thus, have no expression.

Applications:

 

·         Specific gene silencing using RNAi in cell culture.

·         Cancer treatments

·         RNA interference has been used for applications in biotechnology.

·         Useful in epigenomic analysis and clinical application of molecular diagnosis.

·         Neuro-degenerative disorders treatment.

 

Mitochondrial DNA:

  • In addition to DNA in the nucleus, some DNA is also present in the mitochondria.
  • During fertilization the nuclear DNA is formed with 46 chromosomes (i.e., 23 from mother & 23 chromosomes from the father).
  • The Mitochondrial DNA has only one chromosome and its codes for only specific proteins responsible for metabolism.
  • Mitochondrial DNA is inherited only from the mother & thus it is more effective to trace human ancestry.

 

THREE PARENT BABY

  • Three-parent baby, human offspring produced from the genetic material of one man &two women through the use of assisted reproductive technologies, specifically mitochondrial manipulation (or replacement) technologies & three-person in vitro fertilization (IVF).
  • This mechanism involves the replacement of a small amount of faulty DNA in a mother’s egg with healthy DNA from a second woman.
  • The idea is to prohibit certain genetic diseases being passed on to children.
Indian Cancer Genome Atlas (ICGA): Aims to create indigenous, open-source database of molecular profiles of all cancers prevalent in Indian population.

Embryo Transfer Technology:

  • Embryo transfer refers to a step in the process of assisted reproduction in which embryos are placed into the uterus of a female with the intent to establish a pregnancy.
  • This technique (which is often used in connection with ‘In vitro fertilization’ (IVF)), may be used in humans or in animals, in which situations the goals may vary.
  • First performed in 1984.
  • Factors that can affect the success of embryo transfer:
    1. Endometrial receptivity,
    2. Embryo quality and
    3. Embryo transfer technique.

GM Mosquitoes (GMMs):

  • GMMs are mosquitoes that have been implanted with a gene or bacteria which was not originally present or naturally occurring in the insect.
  • Why GMMs?
  • Each year, more than 700 000 people die from vector-borne diseases (VBDs) such as malaria, dengue, yellow fever, Zika virus etc.,
  • Hence, there is an urgent need for new tools to combat
  • What does it do?
  • GMM approaches aimed at suppressing mosquito populations &reducing their susceptibility to infection, as well as their ability to transmit disease-carrying pathogens.
  • The WHO stand on GMMs:
  • According to the WHO statement, GMMs could be a valuable new tool in efforts to eliminate malaria & to control diseases carried by Aedes
  • WHO cautions, however, that the use of GMMs raises concerns& questions around ethics, safety, governance, affordability & cost–effectiveness that must addressed.

 

Human Genome Project (HGP)

  • HGP was the international, collaborative research program whose goal was the complete mapping and understanding of genome (all the genes) of human beings.
  • This was first articulated in 1988 by a special committee of the S. National Academy of Sciences

 

HGP findings:

  • HGP was began in 1990& completed in 2003.
  • It led to the decoding of the entire human genome by sequencing & mapping all of the genes of humans.
  • The HGP gave us the ability, for the first time, to read nature’s complete genetic blueprintfor building a human being.

 

Benefits:

  • Can help us better understand diseases to direct appropriate treatment
  • More accurate prediction of their effects
  • Advancement in forensic applied sciences etc.

 

Genome India Project (GIP)

  • It is aimed at studying the diversity of Indians and its impact on lifestyle, environment & genes that is inherited.
  • GIP also called, ‘Bioscience Mission for Precision Health & Optimal Well-being’.
  • GIP is a combined initiative of Ministry of Health and Family Welfare, Department of Health Research &Department of Biotechnology.
  • Nodal point: the IISc’s Centre for Brain Research.
  • The first stage of the project will look at samples of “10,000 persons from all over the country” to form a “grid” that will enable the development of a “reference genome”.

 

 

The Cancer Genome Atlas (TCGA):

  • Landmark cancer genomics program, characterized over 20000 primary cancer and matched samples spanning 33 cancer types.
  • Minister of Science and Technology inaugurated the 2nd TCGA 2020 conference in New Delhi.
Indian Cancer Genome Atlas (ICGA): Aims to create indigenous, open-source database of molecular profiles of all cancers prevalent in Indian population.

Cloning: Cloning is the process of producing individuals with identical or virtually identical DNA, either naturally or artificially.

 

GM Crops & associated issues

  • Genetically Modified (GM) Seeds: Genetic engineering aims to transcend the genus barrier by introducing an alien gene in the seeds to get the desired effects. The alien gene could be from a plant, an animal or even a soil bacterium.
  • Genetic modification is done in GM crops to confer a particular trait with one of the following properties:
  • Increased yield of a crop
  • Increased nutritional content of a crop
  • Developing resistance to:
  1. Abiotic factors like temperature, salinity or herbicide resistant
  2. Biotic factors like insects

 

GM Crops in India:

  • Bt cotton, it has two alien genes from the soil bacterium Bacillus thuringiensis (Bt) that allows the crop to develop a protein toxic to the common pest pink bollworm.
  • Ht-Bt (Herbicide Resistant) Cotton is derived with the insertion of an additional gene, from another soil bacterium, which allows the plant to resist the common herbicide glyphosate.
  • In Bt brinjal, a gene allows the plant to resist attacks of fruit & shoot borer.
  • In DMH-11 Mustard, genetic modification allows cross-pollination in a crop that self-pollinates in nature.
  • Across the world, GM variants of maize, canola &soyabean, too, are available.
  • Bt Cotton is the only GM crop that is allowed in India from 2002.
  • Ht-Bt Cotton is not allowed to be cultivated in India.
  • Bt Brinjal is under an indefinite moratorium on commercial cultivation since 2010 in India.
Regulatory Authorities:

  • GM Food: FASSI regulates manufacture, storage, distribution, sale & import GM food.
  • For GM Crops: Genetic Engineering Appraisal Committee (GEAC)under MoEF&CC

 

Biotechnology in India:

  • The remarkable march of India into the world of biosciences and technological advances began in 1986. (Mr. Rajiv Gandhi period)
  • In 1986, a separate Department for Biotechnology, within the Ministry of Science & Technology, GoI was created.
  • Vision: “Attaining new heights in biotechnology research, shaping biotechnology into a premier precision tool of the future for creation of wealth & ensuring social justice especially for the welfare of the poor.”
  • BT has made a huge impact on Indian agriculture, healthcare, industry and environment on one hand, while raising global standing of India.
  • The National Biotechnology Development Strategy (2015-2020) aims to make India a US$ 100bn Bio-economy by 2025.

 

BIO-Technology Kisan programme:

  • Farmer-centric scheme, by DBT Ministry of Science & Technology.
  • Pan India program to stimulates entrepreneurship and innovation in farmers and empowers women farmers.
  • Aims to understands the problems and provide simple solutions to farmers.

 

Bio-economy or bio-techonomy:

  • It refers to all economic activity derived from scientific & research activity focused on biotechnology.
  • It is closely linked to the evolution of the biotechnology industry.

 

Major initiatives of the National Biotechnology Development Strategy

  • Launch four major missions in Healthcare, Food & Nutrition, Clean Energy and Education.
  • Create a technology development & translation network across India with global partnership.
  • Ensure strategic & focused investment in building the human capital by setting up a Life Sciences & Biotechnology Education Council.

 

Biotechnology Regulatory Authority of India (BRAI)

  • BRAI is a proposed regulatory body to regulate the use of Genetically Modified Organisms (GMOs), as per the provisions of the Bill introduced in the Parliament in 2013.
  • BRAI was needed as India had signed the Cartagena Protocol and the Protocol mandates setting up of a Regulatory Body.

 

Genetic Engineering Appraisal Committee (GEAC)
·         The GEAC functions under the MoEF&CC.

·         It is responsible for the appraisal of activities involving large-scale use of hazardous microorganisms and recombinants in research & industrial production from the environmental angle.

·         Also responsible for the appraisal of proposals relating to the release of GE organisms & products into the environment including experimental field trials.

·         GEAC is chaired by the Special Secretary/Additional Secretary of MoEF&CC and co-chaired by a representative from the Department of Biotechnology (DBT).

 

Recombinant-DNA (R-DNA) Technology:

  • R-DNA is a “genetic engineering” technology used for producing Artificial DNA through the combination of different genetic materials from different sources.
  • R-DNA involves several steps in specific sequence such as:
    1. Isolation of DNA,
    2. Fragmentation of DNA,
    3. Isolation of a desired DNA fragment,
    4. Ligation of the DNA fragment into a vector,
    5. Transferring the R-DNA into the host,
    6. Culturing the host cells and extraction of desired product.

Application:

  1. In Gene Therapy to correct gene defects.
  2. Useful in detecting presence of Human immunodeficiency virus. (ELISA test)
  3. Production of Insulin.