Evolution of Drosophila head morphology

One major question in Evolutionary Biology concerns the molecular basis of morphological variation. In the last decade a growing amount of data has been accumulated identifying the genes underlying morphological evolution. Further dissection of the genetic changes resulted in the identification of regulatory or coding sequence differences, for some cases even at the resolution of single nucleotides. So far, it is hotly debated whether coding or regulatory changes are the main forces in morphological evolution.
In different Drosophila species considerable variation in the size and shape of complex eyes exists. Since a tremendous knowledge about the function and the development of the eyes in Drosophila melanogaster exists, eye size and shape differences are perfectly suited traits to analyze the molecular basis of variation in a complex organ.

Therefore, we aim to analyze the developmental basis of the observed eye size differences applying methods like mapping approaches, Immunohistology in eye-antennal discs and transcriptome sequencing (RNAseq) for different developmental stages. By exploiting the possibility to hybridize closely related Drosophila species, we aim to investigate the relative influence of cis- and trans-regulatory changes on gene expression levels in eye specific tissue. Furthermore, we are trying to gain insights into the evolution and function of the light-sensitive proteins (Rhodopsins) by analyzing their expression in different Drosophila species.

Alistair McGregor (Oxford Brookes University, UK)