In a discovery that has forcibly removed DNA from the spotlight RNA has become the leading player. Many geneticists world wide have been battling with the question of why organisms are showing traits that don’t come from DNA or from the environment. RNA transference could be the answer.
The Kit gene in mice was the centre of Rassoulzadegan’s study when an abnormality arose. The Kit gene, when mutated, causes a white pigmented patch on the end of the mouse’s tail and feet. However, when two mice mated many of their progeny with wild type genotypes displayed mutant phenotypes. Therefore, these mice must somehow (other than by means of DNA) have inherited the paramutated gene for white tails and feet.
Ashe and Whitelaw discovered that the Kit paramutation causes many abnormal RNA molecules to occur in the sperm. This means that the paramutated RNA is transferred from parent to progeny.
The ground breaking discovery of paramutations crossing the generational gap has been proven with many diverse organisms that also display such results. The question to be asked is; do we therefore inherit diseases such as cancer through RNA and if so, how easily can we prevent the paramutation occurring in offspring.
References:
Ashe, A. and Whitelaw, E. 2006. "Another role for RNA: A messenger across generations" Trends in Genetics Vol 23 No. 1 pp 8-10
Pearson, H. 2006. "Mutant mice challenge rules of genetic inheritance" BioEd Online
Rassoulzadegan, M. et al. 2006. "RNA-mediated non-mendelian inheritance of an epigenetic change in the mouse" Nature 441 pp 469-474
