Transgenic plants

1. Transgenic plants How are they produced?

2. Review of Basics • All organisms contain DNA • DNA contains coded information (genes) for making proteins • Proteins are produced using information from the DNA through a process called protein synthesis • The proteins a plant makes determine its characteristics or traits

3. Basics as a flow chart transcription translation TRAIT

4. DNA can be cut • Genetic engineers use restriction enzymes to cut DNA • Genes coding for specific traits can be isolated from an organism

5. DNA can be transferred • A gene cut out of the DNA of one organism can be inserted into a second organism • The protein coded for by the gene will be produced by the second organism

6. Gene regulation • Genes are turned on and off by regulator genes also found in an organisms DNA • When genetic engineers want to move genes from one organism to another they must also understand how the gene will be regulated in the second organism

7. Cloning the gene • After the gene with the desired characteristic is isolated it is inserted into a bacteria • The bacteria reproduces and makes identical copies of the gene • Each copy is a clone • Many, many clones can be made this way

8. Making a transgene • After the gene is cloned it is prepared for insertion into a second organism • The gene needs: • A section of DNA to turn it on (promoter) • A section of DNA to turn it off (terminator) • A section of DNA to identify the gene (marker)

9. A transgene has four parts

10. Tissue cultures are prepared • Cells from the second plant are isolated • A mass of undifferentiated cells are grown in a culture medium • This group of cells is called a callus

11. The Gene Gun • The gene gun uses gold particles coated with transgenes • These particles are “shot” into the nucleus of the cells in the callus • Hopefully when the gold dissolves, the marked transgenes get incorporated into the DNA of the callus cells

12. The transformation • The callus cells have been transformed to contain the transgene • The callus cells are grown into a plant

13. The transgenic line • The transgenic plants grow and produce seeds • These plants are usually not very strong and would not grow well out in the field • Seeds produced by self-pollination from the transgenic line are called inbreds

14. Backbreeding • These inbred plants are crossed with hardier plants and hybrids are produced • These hybrids are grown and seeds are harvested from the ones found to contain the new gene

15. Graphic of the process