Arrangements Forensic uses DNA profiling: relies on repetitive, hypervariable DNA and not genes per se. Stages involved: DNA isolation, restriction enzyme digestion, gel electrophoresis, blotting DNA onto a filter, hybridisation with a probe. Use of single locus probe.

Learning Objective To explain how DNA technology has been adapted foe use by forensic scientists.

Forensic Uses DNA profiling DNA fingerprinting Out with the old In with the new DNA profiling A sample of DNA from a suspect can be matched with that of a reference sample. PCR is used to amplify minute samples of DNA

DNA profiling Uses minisatellite regions Steps Variable number tandem repeats (VNTRs) Steps DNA isolation, restriction enzyme digestion, gel electrophoresis, blotting DNA onto a filter, hybridisation with a probe

Probes Binds to a specific base sequence on target fragments Multi-locus probes More complex patterns Single locus probes

DNA profiling Short tandem repeats (STRs) A.k.a. microsatellites PCR based technique Uses fluorescent labels and automated DNA detection equipment.

Arrangements Agriculture - Transgenic plants Transgenic plants are engineered by using a plasmid from Agrobacterium. Foreign DNA carrying genes for the desired characteristics inserted into bacterial plasmid. Plant cell protoplasts incubated with bacteria containing genetically engineered plasmid in medium which allows only those plant cells which have taken up the foreign DNA to grow. Illustrate application by transgenic tomato plants: gene for bacteria toxin transferred to plants resulting in effective protection from insect damage.

Arrangements Agriculture - Transgenic plants Moral and ethical issues relating to the use of transgenics.

Arrangements Agriculture - BST Production of bovine somatotrophin (BST) by genetic engineering and its use in cattle. Gene for BST cloned into a bacterial system. Product purified and administered to cattle by injection or in feed. BST increases milk production.

Learning Objective To describe the production of transgenic or GM crops Explain why a plasmid from Agrobacterium is used Explain how foreign DNA is isolated and inserted into plasmids Explain how plants containing recombinant DNA can be grown and expanded Describe the production of transgenic tomato plants To list some potential uses of GM plant technology

Learning Objective To describe the production of BST To describe the use of BST

Keywords - Activity Find the meaning of the following words Microinjection Transfection Transformation Transgene Transgenic DNA cloning

DNA technology and Agriculture Two uses of DNA technology in agriculture Production of Transgenic organisms Transgenic plants Production of growth hormones using recombinant DNA methods. Bovine growth hormone

Transgenic plants Requirements Ti Plasmid Suitable vector Mechanism for regenerating whole plants Ti Plasmid Found in soil bacterium Agrobacterium tumefaciens (crown gall disease)

Preparation of Ti plasmid The Ti plasmid can integrate DNA into plant cell genome Stages Remove tumour inducing genes Insert gene and marker Culture plasmid and protoplasts Stimulate cell wall development Callus formation Seedling formation

Transgenic plants FLAVR SAVR tomato Insect resistance Production of ethylene is inhibited to delay the ripening process. Insect resistance Insert a gene from Bacillus thuringiensis that produces an insecticidal protein Introduction of nitrogen fixation genes into non-leguminous plants. Disadvantage of Ti-based vector system Can only work for dicotyledonous plants A lot of crops are monocotyledonous.

Bovine Growth Hormone bovine somatotrophin (BST) Increases milk yield by 10% Improves weight gain in beef cattle by diverting resources to cell and protein production, suppresses the production of fatty deposits.

Learning Objective To list potential uses of DNA technology To understand some of the moral and ethical issues raised by the production of transgenic plants and animals.