2Applications of Biotechnology Biotechnology: The use of organisms to perform practical tasks for human use.DNA Technology: Application of biotechnology in which genomes of organisms are analyzed and manipulated at the molecular levelBacteria, such as E. coli, serve as useful models for gene manipulationsDo not undergo meiosis (reproduce asexually)Still have means of genetic recombinationThis natural recombination process is capitalized on in current DNA technology procedures
3Selective Breeding Cross-breed organisms with desired traits Enhance expression of traitProduce combination of desired traits
5The Human GenomeAn organism’s complete set of genetic material, defined by order of DNA bases is known as its genomeDNA is thousands of times longer than the diameter of the nucleusDNA is able to fit into the nucleus because of an elaborate packing system
6The Human Genome Project 13 year project to sequence the entire human genome (nucleotide sequence)Knowing sequence is just the first step, must then distinguish between non-coding (introns) and coding (exons) regionsFinally functions of all resulting polypeptides must be determinedGene identification is useful in evolutionary research as well as diagnosing , treating and possibly preventing diseases/disorders.
7Recombinant DNA Technology Combine genes from different sources, even different species, into a single DNA moleculeBacteria have small circular pieces of DNA called plasmids separate from their larger single chromosomePlasmids can replicate and pass between bacterial cells allowing gene sharing – associated with antibacterial resistance
8Genetic EngineeringPlasmids are used to add genes for useful products into bacteria through a process called gene cloningRemove plasmidAdd useful geneReinsert in bacteria where genes are copied many times
11How can we do this?Restriction enzymes are proteins that cut genes at specific DNA sequences.Over 75 different kinds of restriction enzymes are known; each one “recognizes” and cut DNA at a particular sequenceRestriction enzymes allow DNA to be cut into fragments that can be isolated, separated, and analyzed.The cut ends produce matching “sticky ends” on the DNA fragment and the cut plasmids.
12Restriction Enzyme Action & Cloning into a Plasmid Animation – Steps in Cloning a Gene
15Genetic Manipulation of Plants Genetic engineering of plants is much easier than that of animals.natural transformation system ( Agrobacterium tumefaciens)plant tissue can re-differentiatetransformation and regeneration are relatively easy for manyThe soil bacterium Agrobacterium tumefaciens can infect wounded plant tissue, transferring a large plasmid, the Ti plasmid, containing contains genes for the synthesis of (1) food for the bacterium, and (2) plant hormones.This plasmid has been genetically modified ("disarmed") and used to insert a gene that can be used as a selectable marker as well as a gene of interest, such as herbicide resistance, virus tolerance, decreased sensitivity to insects or pathogens.DNA can now be delivered into the cells by small, µm-sized tungsten or gold bullets coated with the DNA. The bullets are fired from a device that works similar to a shotgun called a gene gun.ANIMATION
16Natural v. Artificial Twinning Animation CloningNatural v. Artificial Twinning AnimationCloning Animation
20Uses of Electrophoresis Isolation of DNA fragments so that they can be incorporated into a plasmids or some other vector. Creating a DNA map so that we know the exact order of the nucleic acid base pairs (A, T, C, or G) along a DNA strand.Perform DNA Fingerprinting, which can be used to test organic items, such as hair or blood, and match them with the person that they came from. This is useful in criminal investigations.DNA Fingerprinting Animation
21Polymerase Chain Reaction Method of photocopying DNA in vitro to provide large supply to avoid needing large sample size of cells to extract it (DNA) from.Animation
22Prokaryotic Control of Gene Expression Animation 1Animation 2
23Eukarotic Controls of Gene Expression Gene expression is the transcription and translation of genes into proteinsEukaryotic controls are elaborate than prokaryotesGenes are not controlled in clustersProteins called transcription factors regulate transcription by binding to promoters or RNA polymeraseTurned ON or OFF by chemical signals in the cell
24Cellular Differentiation STEM CELLS are cells that are undifferentiated and have the potential to differentiate into various types of cells
25Homeotic Genes“Master switches”; control formation of body parts in specific locationsSmall changes in these genes can result in major morphological changes