Variation in gene expression during embryogenesis in Drosophila strains and species. Asli Kayserili, Alex Kalinka, Pavel Tomancak. Max Planck Institute for Cell Biology and Genetics Pfotenhauerstrasse 108, Dresden, Germany.

   In nature, we observe phenotypic variation within species as well as between species. The ratio of between-species to within-species variation can tell us about the type of evolutionary forces acting on the underlying genes. To discover how different genes involved in embryogenesis are evolving, we measured the variation of gene expression in early embryos of D. melanogaster inbred lines from North Carolina (DGRP). We focus on gene expression because we can directly analyse the effects of genetic variations in the regulatory elements. In this study, we analyse the amount of variation seen in inbred lines, and compare it to five of the sequenced Drosophila species. In addition, we estimate the importance of local adaptation by comparing D. melanogaster strains from North America with D. melanogaster strains from Africa. Our results show that there is substantial variation in gene expression during Drosophila embryogenesis, which is important for divergence between both populations and species.