Ian Wilmut and Cloning :: Genetic Engineering Essays

Ian Wilmut and CloningBefore Dolly the cl unrivaledd sheep made news headlines, the aforesaid(prenominal) researchers had only the year before raised seven other sheep from oocytes whose nuclei had been replaced with nuclei from either fetal or embryonic tissue.1 This created a minor stir as this is the outset report to their knowledge, of live mammalian offspring following nuclear transfer from an established cell line.1 The implications of this is that they have provided techniques to analyze and modify gene functions in sheep (By providing clones of the same sheep).1 The key to their success is the serum starvation that the donor cell undergoes, to force the donor cell into a quiescent state, so that it is not replicating its DNA or dividing. This possibly makes the nucleus more susceptible to re-programming by the recipient egg cell. The researchers built on this knowledge, and carried out a nuclear transfer from cells from the mammary secretory organ of a 6-year old ewe in th e last trimester of pregnancy. (instead of fetal or embryonic stem cells). After 277 nuclear transfers, Dolly was born.2 Dolly shows morphological characteristics belonging to the broth (Finn Dorset)that donated the nucleus instead of the oocyte donor or the surrogate mother(Scottish Blackface). Thus erasing any possibility of the birth due to the mating of the surrogate mother with another sheep. In 1975 Gurdon, Laskey & Reeves showed that nuclei transfer from keratinised skin cells of liberal frogs supported growth to the tadpole stage 3. Wilmuts experiment took one step further and managed for the existence(Dolly) to grow to adulthood, thereby confirming that adult cells do in fact contain workable versions of all the genes necessary to produce an entire organism. Previously there was widespread belief that cells from adult mammals cannot be persuaded to regenerate a whole organism. Now that Wilmut has proven once and for all that this is otherwise, many cloning experiments th at were once fantasy could now be accomplished. For example, an organism of engross can be cloned from any living cells from it if it no longer can reproduce normally (perhaps due to defects in gametes formation) or if only cultured cells of the organism of interest remains (it has already died but complete cell death has not occurred). However, it will take some time before Wilmuts technique is utilize as an important aid in all manner of biological and biomedical investigations. As forementioned, having to do 277 nuclear transfer just to obtain one living sheep is impractical for most experiments.