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Cloning

Cloning. Describe the production of natural clones in plants: vegetative propagation in elm trees. What is a clone?. E.g. Bacterial populations, identical twins, strawberry plants. Clone: gene, cell or organism which carries same genetic information from the same original DNA.

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Cloning

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  1. Cloning Describe the production of natural clones in plants: vegetative propagation in elm trees

  2. What is a clone? E.g. Bacterial populations, identical twins, strawberry plants Clone: • gene, cell or organism which carries same genetic information • from the same original DNA Careful! Make sure you distinguish between cloned genes, cloned cells or cloned organisms

  3. Advantages Quick No need for another organism (if sexual rep impossible) All offspring have alleles which enable survival Disadvantages No genetic variation: population may be vulnerable to change in environment Asexual reproduction

  4. Vegetative reproduction by suckers

  5. How it works Destruction of main trunk  • Root suckers / basal sprouts appear • From meristem tissue in trunk • Close to ground • Forms circle of new growth- clonal patch

  6. Advantages Helps plants spread Enables survival following damage to parent tree (disease, burning, felling) Disadvantages Susceptible to disease- no genetic variation E.g. Dutch elm disease fungal disease carried by beetle Asexual reproduction in plants= vegetative propagation (in elm trees) Now do questions on p153

  7. The pathogen, the vector and the damage Ophiostoma ulmi. Ulmus procera Scolytus multistriatus

  8. Questions • What advantage would it be for elm trees to reproduce both sexually and asexually? • Why is it called vegetative? • Describe how varieties of elm tree might be produced which are resistant to Dutch elm disease.

  9. Artificial clones and agriculture • Describe the production of artificial clones from tissue culture • Discuss advantages and disadvantages of plant cloning in agriculture

  10. Micro-propagation • Definition: • Growing plants from seed or small pieces of tissue under sterile conditions on specially selected media • (http://www.rbgkew.org.uk/ksheets/pdfs/k1microprop.pdf#search=%22micro-propagation%22)

  11. The process • stock plant care • explant selection • Sterilization – killing bacteria • media manipulation – using the correct nutrient • acclimation – correct temperature and humidity • growing on of liners.

  12. Micro-propagation • Mass production of plants by placing tiny pieces of plant tissue in sterile glass containers along with nutrients. • Perfect clones of superplants are produced in sterile cabinets, with filtered air and carefully controlled light, temperature, and humidity. • Uses:-the house-plant industry and for forestry – • Gives immediate results, whereas obtaining genetically homogeneous tree seed by traditional means would take over a hundred years. • http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0038573.html

  13. References • http://en.wikipedia.org/wiki/Marker_gene lhttp://www.hort.purdue.edu/hort/courses/hort250/animations/Gene%20Gun%20Animation/Genegun1.html http://www.ncbe.reading.ac.uk/NCBE/GMFOOD/technology.html http://www.biotech.iastate.edu/lab_protocols/AV_Micropropagation.html lhttp://www.hort.purdue.edu/hort/courses/hort250/animations/Gene%20Gun%20Animation/Genegun1.html http://www.ncbe.reading.ac.uk/NCBE/GMFOOD/technology.html http://www.biotech.iastate.edu/lab_protocols/AV_Micropropagation.html http://cls.casa.colostate.edu/TransgenicCrops/teacher%20workshop%20I%207-01_files/frame.htm Powerpoint – v good

  14. Taking cuttings Grafting How it’s done Rootstock Roots develop here, below node Clone of original plant

  15. Tissue culture • Small piece of tissue cut from plant explant • Placed in nutrient growth medium • Mitosis undifferentiated mass- callus • Callus cells placed on growth medium + plant hormones • Plantlets transferred to new growth medium • Then to greenhouse

  16. Advantages Very large numbers of plants Genetically identical- same yield, taste, colour. Free of disease Same time to harvest- reduces cost Disadvantages Susceptible to pests and diseases Micropropagation by callus tissue culture N.B. This is not genetic engineering, but a form of selective breeding

  17. Why must meristem cells be present? • Explain why tissue culture is not genetic engineering • Why might it be useful to graft material from a good ruit producing tree on to a different rootstock?

  18. Cloning in animals: genetically identical organisms • Describe how artificial clones of animals can be produced • Discuss advantages and disadvantages of cloning animals • Outline differences between reproductive and non-reproductive cloning

  19. Reproductive cloning • Produces whole new organisms which are genetically identical to parent 2 methods: 1)Splitting embryos 2)Transfer of nucleus

  20. How is it done? Use the 1st animation on the next slide to find out about: • Artificial identical twins • Somatic cell nuclear transfer / enucleated eggs Then use the 2nd animation to try cloning a mouse ☺ Review the whole process using 3rd one

  21. Cloning animations • http://learn.genetics.utah.edu/content/tech/cloning/whatiscloning/ • http://learn.genetics.utah.edu/content/tech/cloning/clickandclone/ • http://www.dnalc.org/resources/animations/cloning101.html

  22. Advantages Disadvantages Advantages and disadvantages

  23. Non-reproductive cloning Uses cloned cells to produce new cells, tissues and organs

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