Institute Cytology and Genetics

Laboratory of The Molecular Bases of Animal Genetics

Head A.G. Romashchenko, Ph.D.

A hierarchical-block arrangement of Bsp-repeats

The Laboratory is performing combined basic and applied research relevant to problems of the variability of the genome and gene structure in eukaryotes in the course of their macro- and microevolution. The major achievements of the Laboratory include:

  • Discovery of DNA repeated sequences (Bsp-repeats) specific to Canidae that were involved in the genomic reorganization of species of the Canidae family (Carnivora) during speciation.

  • Description of the steps of molecular evolution using modern computer methods for analysis of primary DNA. Comparative analysis of the structure of the hierarchically block arranged taxon-specific repetitive DNA from the silver fox, grey fox, domestic dog and raccoon dog to detect 5 types of subrepeats common to all the species.

    All the 5 variants of subrepeats have diverged from a common ancestral DNA sequence. The establishment of the complex hierarchical structure of repetitive DNA took 50-60 million years. In contrast, the time of the emergence of the now living contemporary species, wolf, dog, fox, arctic fox and other canids, dates back to 5-10 million years. The major elements of repetitive DNA (subrepeats, monomers) have emerged before speciation. Therefore, the major steps of molecular evolution of the taxon-specific repeats preceded speciation in Canidae.

  • Identification of the possible mechanisms of structure formation and informational saturation of DNA molecules of regulatory type exemplified by increasing complexity of both DNA structure and the potential functional loading in the different variants of the Bsp-repeats.

  • Obtainment of the first data about the evolutionary features of the gene pools of mitochondrial DNA in human populations of Siberia by comparative analysis of DNA samples from the remains of individuals buried 1,000-2,000 B.C. with those from contemporary inhabitants of the same geographical site.

  • Analysis of the spread of the allelic variant of the chemokine CCR5 receptor with deletion (delta32) affecting susceptibility to infection in numerous populations of the Eurasian territories.

  • Detection of the polymorphic sites in the gene for the macrophage colony stimulating factor receptor (c-fms) performing important functions in the regulation of monocyte/macrophage differentiation and proliferation. Genotyping of the polymorphic site in the 3' flanking region of the c-fms gene occurring in the Siberian population indicated that the rare variant is very frequent in the Europeoid (22-26%), Arctic (20-23%) and Central Asian (31-42%) populations. An association of the c-fms gene with human response to environmental factors, radiation in particular, was established.