Advance in genetic engineering ppt
- 2. Topic Screening of transformed analysis In tissue culture NAME: JAYGENDRA KUMAR Ph.D.(AG)BIOTECHNOLOGY
- 3. cont.….. Transformation Transformation elements Tissue Culture Gus expression How is Tissue Culture Done Alternative to Tissue Culture Selectable Marker Genes
- 4. Transformation Transformation is the step in the genetic engineering process where a new gene (transgene) is inserted into a single plant cell. The process can be difficult because the genetic engineering must all of the following before they are successful. Transformation is the step in the genetic engineering process where the new gene is inserted into a single plant cell.
- 5. The new gene must be delivered into the nucleus of a cell and insert into a chromosome. The cells that receive the new gene must stay alive. The cells and plants that contain the new gene must be easily identifiable (selectable markers). The transformed cell must divide and give rise to an entire plant. The location where the transgene inserts into the chromosome must not interfere with the expression of the gene.
- 6. Transformation elements > Explant > Agrobacterium tumefacien and Agrobacterium rhizogenes > DNA: plasmid; DNA fragment > Selection marker and promoter
- 7. The other technique is transformation where genetic engineers introduce the gene into these clustered cells using one of several possible methods including: Agrobacterium tumefaciens. > The gene gun (particle bombardment) > Electroporation > Microfibers.
- 8. Tissue Culture The tissue culture process is used by crop genetic engineering because seeds and plants consist of billions of cells. Through tissue culture the transformed cell can then be regenerated into an entire plant with each cell containing the transgene.
- 9. GUS expression The GUS gene creates blue coloration of transformed tissue when transformed cells or tissues are provided with the appropriate substrate
- 10. How is Tissue Culture Done? Tissue culture is an important component of transforming plants with new genes. During this procedure, plant cells can be removed from various parts of a plant and placed on media in petri plates. The media does not contain the growth hormones normally present in a plant that tell the cells which tissue to develop . As a result, the cells do not differentiate and instead form a mass of cells called a callus that are not differentiated into at the tissue level.
- 11. Cells are taken from plants and grown into undifferentiated masses called callus. Immature embryos are removed from seeds and placed on media. Callus cells will then begin to grow from them. Callus are masses of undifferentiated cells.
- 12. Alternative to Tissue Culture genetic engineers have by passed the tissue culture process by producing plants with the transgene in the germline cells. This means that they introduced the new gene into some but not all of the cells in a young plant. Some of the cells in the seedling that genetics have transformed are those that divide and develop into the pollen or egg producing tissues in the plant (the germline). Another transformation method that could potentially tissue culture is the transformation of pollen. In a species such as corn, the transformed pollen could be used in a cross with the hope that some of the progeny will inherit the transgene.
- 13. Selectable Marker Genes callus cells have gone through the transformation process, it takes weeks of recovery and growth in a petri dish before they can develop into plants. Thousands of cells are growing on a single petri dish, but only a few may actually have received the new gene. It would be very cumbersome to grow up each cell into a plant to test for the presence of the transgene. It is much more efficient for genetics to determine which cells have been transformed while still at the cellular level.
- 14. The steps in tissue culture : Tissue samples are taken from a plant (explanting). The samples are grown on media and masses of undifferentiated cells begin to grow. The undifferentiated cells can be manipulated (procedures such as, DNA extraction and transformation with a transgene and selectable marker Growth hormones are added to the media causing the cells to multiply and differentiate into entire plants.