Date(s) : 06/03/2017 iCal
11 h 00 min - 12 h 00 min
The past 20 years of comparative developmental genetic studies have shown that the formation of morphological traits is under the control of genetic regulatory networks made of evolutionary conserved components. However it remains unclear how alterations of those networks lead to morphological innovations.
The evolution of a pigmentation spot located on the wing of some Drosophila males is a great model to tackle this question, notably because it is genetically tractable and has evolved several times in the melanogaster group.
Using a comparative and integrative approach we are mapping on the drosophila tree the genomic changes that caused changes in the genetic regulatory network of wing pigmentation. During the presentation we will introduce our methodology as well computational and statistical challenges. In order to identify genes whose changes in spatio-temporal expression underlie the evolution of wing pigmentation, we are comparing gene expression using RNA-seq throughout wing pupal development in 3 different species and between sexes. In order to understand the genetic determinism of these gene expression changes we are investigating transcriptional regulatory changes between conditions. To this end we have opted for a dual strategy: we have employed functional genomics methods such as ChIP-seq and ATAC-seq to identify regulatory sequences and we are comparing transcription factor binding sites composition between species. We are testing the involvement of a dozen candidates in the evolution of wing spot formation by using a combination of CRISPR/Cas9-targeted mutagenesis, RNAi knockdown and overexpression assays in pupae of the spotted species D. biarmipes.