Introduction of dna into non bacterial cells
- 1. INTRODUCTION OF DNA INTO NON BACTERIAL CELLS Presented By: Hifza Bibi
- 3. Transformation of individual cells Liposomes Protoplast Electroporation Microinjection Biolistic
- 4. 1) Liposomes. With most organisms the main barrier to DNA uptake is the cell wall. Cultured animal cells, which usually lack cell walls, are easily transformed, especially if the DNA is precipitated onto the cell surface with calcium phosphate or enclosed in liposomes that fuse with the cell membrane.
- 6. 2) Protoplast. Enzymes that degrade yeast, fungal, and plant cell walls are available, and under the right conditions intact protoplasts can be obtained .Protoplasts generally take up DNA quite readily.
- 7. 3)Electroporation. The cells are subjected to a short electrical pulse, thought to induce the transient formation of pores in the cell membrane, through which DNA molecules are able to enter the cell. After transformation the protoplasts are washed to remove the degradative enzymes and the cell wall spontaneously re-forms.
- 8. PHYSICAL METHOD 1.Microinjection 2.Microprojectile 1) Microinjection. The first of these is microinjection, which makes use of a very fine pipette to inject DNA molecules directly into the nucleus of the cells to be transformed . This technique was initially applied to animal cells but has subsequently been successful with plant cells. 2) Microprojectile. The second method involves bombardment of the cells with high velocity microprojectiles, usually particles of gold or tungsten that have been coated with DNA. These microprojectiles are fired at the cells from a particle gun. This unusual technique is termed biolistic and has been used with a number of different types of cell.
- 11. Transformation of whole organisms. Plants are relatively easy to regenerate from cultured cells. A single transformed plant cell can therefore give rise to a transformed plant, which carries the cloned DNA in every cell, and passes the cloned DNA on to its progeny following flowering and seed formation. Animals, of course, cannot be regenerated from cultured cells, so obtaining transformed animals requires a rather more subtle approach. One technique with mammals such as mice is to remove fertilized eggs from the oviduct, to microinject DNA, and then to reimplant the transformed cells into the mother’s reproductive tract.