Molecular Organization and Polymorphism of 5S rDNA in Carpathian Bees

The natural distribution area of the western honey bee, Apis mellifera L., covers Europe, West Asia and Africa. Adaptation to local environmental conditions resulted in the formation of numerous subspecies and ecotypes of western honey bee, which represent a convenient model for studying the microevolution of insects. Genomic region encoding 5S rRNA (5S rDNA) is a popular tool for investigation of the molecular evolution and phylogeny of closely related animal and plant taxa. In this article, we present the results of the analysis of 5S rDNA polymorphism in two breeding races, Rakhiv and Hoverla, of the Carpathian breed of western honey bee, which represents the local ecotype of the subspecies A. m. carnica, and compare them with the data available in the Genbank database for this subspecies and the Asian species A. cerana. It was found that in the genome of A. m. carnica there are at least two classes of 5S rDNA, each of which includes several structural variants. The genomes of the two studied races of the Carpathian breed and that of the A. m. carnica from Genbank differ in the sets of such variants, while the 5S rDNA repeated units of the of A. cerana are identical within the genome. The obtained results indicate a high intra- and intergenomic polymorphism of 5S rDNA in A. m. carnica.