Plant and Animal Biotechnology ApplicationsRead Chapter 10

Humans dependent on crops for foodWorld population expandingRequirement of:Optimization of agriculture efficiencyIncrease in productivity

How can this be achieved?Increase crop yields (new varieties)Increase nutrition valueDisease resistant plant/cropsInsect resistant plant/cropsIncrease post harvest life

Agriculture (plants and animals)

Methods for improvement in quality and productivity of crops Classical plant breeding

Practiced since ancient times

Breeds with different desired characteristics are used for deliberate interbreeding (cross breeding)

Breed 1 (wheat) = Good yield but not resistant to disease

Breed 2 (wheat) = Poor yield but resistant to disease

Cross breed produces progeny (hybrid) with desired trait i.e. disease resistant + high yielding crop (wheat)

Classical Plant breeding

Modern bio-techniques for improvement of quality and productivity of crops MicropropagationProtoplast fusionGenetic engineering of plants Using agrobacter (dicot only) Gene gun/particle gun/shotgun technique

Micropropagation (Clonal propagation)The technique of asexual or vegetative propagation (multiplication) of plants in vitro (test tubes) from small sections of plant such as stem tip, root tip. node, meristem, embryo or seed etc. Steps/stages:Selection of plant material (plant with desired trait)Testing for no infection (virus/bacteria)Establishment of aseptic culture (free from microbes)Callus (mass of undifferentiated cells) formation Multiplication (callus cells)Shoot elongation (specific plant hormones)Root formation (specific plant hormones)Plant establishment in small potsTransplantation in field

MicropropagationBanana, Oil Palms, Coffee plants etcThe plus points

Rapid multiplication Pathogen removal Uniform plants (clones) Germplasm stored, not seeds. Embryos can be rescued.

Somaclonal variationCells from a single plant are taken and grown.It can give rise to variations.Normal Tissue cultureReasons for variation:Plant cells can be at different stage of growthGrowth conditions differentEnvironment conditions differentMutationsChromosome number variation

Protoplast FusionPotato, tomato, pepper, tobacco plants have been regenerated from protoplastsTomatoPotatoHybridPomato

Plant Genetic EngineeringFirst practical system for gene transfer in plants in 1983 using Agrobacterium tumifaciens (Agrobactor) Agrobactor contains Ti Plasmid (T-DNA) Tumor inducing (Ti) plasmidTi plasmid is transferred into plant genome. Ti Used as vector for inserting gene in plants (foreign gene incorporated in Ti plasmid)Good for dicot plants because agrobactor infects only dicotsMonocots: gene gun techniquePlant cells are bombarded with plant DNA coated nanogold particles.

Why genetic engineering for plants?Interspecies barriers to transfer genes disappear.Traditional breeding methods lack in precision. Improved resistance to herbicides.Improved resistance to plant pathogens and insect pests.Improved post harvest characteristics.

These are also application of plant genetic engineering/protoplast fusion

Gene for Bt toxin incorporated into cotton, tomato and corn.Makes it resistant to insect pestsTransgenic plant: genetically engineered plantsInsect resistant transgenic crops (Biological Control) Example: Bt corn or Bt cotton Bacillusthuringiensis

Improving Post harvest characteristics

NEW FLAVOR SAVER: A tomato modified to contain a flavor gene from lemon basil won a taste test against regular tomatoes

Transgenic soybean plantHealthier/high value cooking oilsContains less saturated fatOil produced from these genetically enginnered plant is good for heart patients

Ethical issues/Biosafety issuesHow safe are these crops for human consumption?Playing with god?Toxic gene from transgenic plant (corn:fodder for cattle) can enter food crop by accidentBioterrorist can misuse the technology/steal transgenic organisms for their useFood produced from genetically engineered plants/animals: harmful? allergiesRead chapter 13 and 14

Animal Biotechnology

Increase milk quantity and quality Transgenic cow which produces milk with low cholesterol for heart patients Disease resistant animals/cattle Increase size of animal/goat, pig, chicken for meat production Fast growing animal for meat production

Selective breeding aims to increase the frequency of a large number of genes that work together with the remainder of the animals genome to produce the desired phenotype (characteristic) 'Fat Cattle' - Duke of Bedford and The Triumphs of Selective Breeding

Transgenic Animal An animal that has acquired novel genetic material by artificial means rather than by normal route of sexual reproduction.OR genetically engineered animal.First Transgenic animal Rat with growth hormone gene inserted.

How is transgenic animal generated?Foreign gene selection and construction (PCR+ vector).Microinjection of DNA in to pronucleus (cell containing separate male and female nucleus/not fused yet) of fertilized egg.Implanting these eggs into surrogate mothers.Developing the embryo to full term.Checking stable and heritable incorporation of foreign DNA in the offspring.Demonstration of transgene being expressed and producing the desired product.

Microinjection of DNA into pronucleus is the main method of gene transfer. It is done by fine glass needles that allow injection of DNA into fertilized eggs.Pronucleus

Transgenic animals are used for biopharmaceutical (human proteins) manufacturingUsed as bioreactors Production of human proteins of pharmaceutical value in animal milk

ProteinAnimalUseAntithrombin IIIGoatReduce the amount of blood needed in some surgeriesFactor VIII, Factor IXGoat, Pig, SheepTreatment of hemophilia (bleeding disorder) (blood clotting protein)CFTRSheepTreatment of cystic fibrosisLactoferrinCowNatural antibiotic and used in coronary surgery Alpha-1-antitrypsinSheepTreatment of cystic fibrosis and emphysemaLysostaphinCowAn anti-bacterial compound that prevents mastitis in cowsSpider silk proteinGoatProduction of ultra-strong, lightweight medical and industrial materials

Biopharmaceutical (biosynthetic human proteins used for therapeutic )Insulin: is a hormone important for glucose metabolism in the body. Insulin causes cells in the liver, muscle, and fat tissue to take up glucose from the blood, storing it as glycogen in the liver and muscle. Insulin stops the use of fat as an energy source. When insulin is absent (or low), glucose is not taken up by body cells, and blood sugar rises causing diabetes Somatostatin: growth hormone (used to treat dwarfism caused due to deficiency of hormone in diseased child.)Interferons: glycoproteins made by our body to fight virus infection and inhibit the growth of cancer cells. Used as medicine to fight some virus infection/treat cancer. Lymphokines: proteins made by immune system of our body to fight various infections (bacteria/fungi/allergy etc)

Gene Therapy Used for the treatment of diseases by the transfer of normal functional gene in a patients body cells to restore the function of mutant abnormal gene.Two types:Germ cell gene therapyHealthy gene is introduced in the patients germ cells so that can be passed on to the offsprings

2. Somatic cell gene therapyHealthy gene is introduced in patients body cells (somatic) lacking it and is not passed onto the offspring.

You should be able to answer the following: (Important)Define/short note: protplast fusion, gene gun, Ti plasmid, Bt crops, micropropagation or clonal propagation, Agrobacterium tumifaciens, How are plants genetic engineered or transgenic plants produced. (Ti plasmid used as vector)How are transgenic animals made?Application of transgenic animal/animal biotechnologyApplication of plant biotechnology