Evolutionary innovations have shaped the diversity of animal and plant forms.
The origin of these evolutionary innovations implies the origin of new regulatory
pathways, which leads to a change in the development pattern. Most evolutionary
innovations as shown by research in a variety of models have suggested that
they are caused not by the appearance of new genes, but rather by the
acquisition of new function by pre-existing genes. Understanding the genetic and
molecular changes which lead to a shift in the developmental pattern leading to
the regulation of the particular trait is therefore one of the key challenges of
evolutionary developmental genetics. Sex comb in Drosophila is a sexually
dimorphic morphological character, which serve as a good model system to
understand how genetic modifications have taken place in the course of evolution
leading to as an evolutionary innovation. Though genetic network controlling the
development of this trait has been studied to some extent in D. melanogaster,
and Sophophoran group, understanding of the changes that have lead to the
origin 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 changes
in the developmental genetic pathway underlying the evolution of the primitive
bristles pattern of Drosophila in general to sex comb as in the Sophophoran
group". Studies in the present project explore the differences in the genetic
regulators viz, Sex combs reduced, dachshund and bric-a- brac from the species
cluster with primitive bristle to species with sex comb of Drosophila.
