Molecular variability in geographically distant populations of Drosophila melanogaster at the Lim3 gene regulating nervous system development

In this study, we compare the variability of the regulatory region of the Lim3 gene, which plays a key role in the development of the nervous system, in two populations of Drosophila melanogaster inhabiting the cities of Aleksandrov (Russia) and Raleigh (United States). The two population areas are located in different geographic regions and differ in their ecology. A comparison of nucleotide sequences of 16 (2010) and 20 (2011) alleles from the Alexandrov population showed that in both cases the variability level of the untranslated Lim3 region was considerably lower than that of the 5’ regulatory region adjacent to the transcription start site. According to quantitative and qualitative parameters of the variability, there was no difference between samples of different years, which indicates the stability of the population inhabiting the northern border of the species areal. The patterns of polymorphic sites are similar in both populations, which suggest a neutral character of the variability found with respect to environmental factors, as well as the importance of nucleotide substitutions in a number of sites of the Lim3 regulatory region with respect to the control of this gene expression.