Genetic Basis For Evolution of Sex

Evolutionary innovations have shaped the diversity of animal and plant forms.The origin of these evolutionary innovations implies the origin of new regulatorypathways, which leads to a change in the development pattern. Most evolutionaryinnovations as shown by research in a variety of models have suggested thatthey are caused not by the appearance of new genes, but rather by theacquisition of new function by pre-existing genes. Understanding the genetic andmolecular changes which lead to a shift in the developmental pattern leading tothe regulation of the particular trait is therefore one of the key challenges ofevolutionary developmental genetics. Sex comb in Drosophila is a sexuallydimorphic morphological character, which serve as a good model system tounderstand how genetic modifications have taken place in the course of evolutionleading to as an evolutionary innovation. Though genetic network controlling thedevelopment of this trait has been studied to some extent in D. melanogaster, and Sophophoran group, understanding of the changes that have lead to theorigin of this new character from the primitive bristles remain to be dissected out.In this context the question asked in the present project is What are the changesin the developmental genetic pathway underlying the evolution of the primitivebristles pattern of Drosophila in general to sex comb as in the Sophophorangroup. Studies in the present project explore the differences in the geneticregulators viz, Sex combs reduced, dachshund and bric-a- brac from the speciescluster with primitive bristle to species with sex comb of Drosophila.