Dolly and the New Age of Cloning :: Genetic Engineering Essays

Dolly and the New Age of Cloning The concept of cloning is not new. Organisms ranging from microbes (for example bacteria) and animals (such as aphids and even certain species of shrimp and snails) have practiced asexual reproduction for millions of years, where the offspring are exact duplicates of the parents. It is also not uncommon to encounter identical twins among the more complex life forms like mammals. Twins are in essence clones as they share the same genetic blueprint. What then is so significant about Dolly? In the research paper published by I. Wilmut, W.A. Ritchie, J. McWhir and K.H.S. Campbell (1), Dolly was described as the first known mammal to be cloned by nuclear transfer from a cultured cell line. This technique is revolutionary as it dispelled a dogma in biology that upholds the notion of differentiated cells, being highly specialized, are irreversibly altered to an extent that would render them unable to inter-convert between cell forms (i.e a lymphocyte is not able to produce a nerve cell and vice versa). Dolly is living proof that a differentiated cell, such as one in the udder of sheep, has not only the potential of creating other tissue forms, but the entire living being. The evidence gathered from Dolly also went one step further to establish that organisms produced in such a way were not disadvantaged in their general physiological or reproductive function. Thus the new age of cloning was born with Dolly as its flagship. The success of Dr Ian Wilmut and his team in creating Dolly sparked global interest. This has greatly benefitted science as it has accelerated the rate at which knowledge is assimilated in the field of cloning. Many attempts have been to clone other mammals (for example cows or pigs). However they do not always yield fruitful results. Dolly can be considered to be a success among 277 failures. Indeed of the 277 oocytes used in the experiment, only one yielded a success. The techniques used in cloning would have to be refined before it can be universally applied. We have now uncovered other interesting facts about Dolly and cloning. For example, Dolly is considered to be "older" than her natural counterparts by a measure of the length of her telomeres that was found to be relatively shorter. However Advanced Cell Technology (ACT) of Worcester, Massachusetts, using different techniques than Dr Ian Wilmut and his team, pro duced calves that were found to have longer telomeres (2).