HORTICULTURE

Detailed explanation-1: -Direct microinjection of DNA into one of the pronuclei of a zygote (Figure 1), has been the most rewarding technique for the production of transgenic mice, rats, rabbits and large domestic livestock such as sheep, pigs and cows.

Detailed explanation-2: -a) DNA microinjection. This method involves the direct microinjection of a chosen gene construct (a single gene or a combination of genes) from another member of the same species or from a different species, into the pronucleus of a fertilized ovum.

Detailed explanation-3: -In mice, the fertilized eggs are harvested from a female. The DNA is then microinjected into the eggs, and the eggs are re-implanted into a pseudopregnant female mouse (the ovum is transferred into the oviduct of a recipient female, or foster mother, that has been induced by mating with a vasectomized male).

Detailed explanation-4: -The injection of a DNA solution into the pronuclei of fertilized eggs is the most common method for making transgenic animals. Injection is done at the stage of development when the zygote has two pronuclei, one from each gamete, which will later fuse to form the diploid nucleus.