Genetic Relationships and Signatures of Adaptation to the Climatic Conditions in Populations of Apis cerana Based on the Polymorphism of the Gene Vitellogenin

SIMPLE SUMMARY: The Oriental honey bee Apis cerana, similar to the Western honey bee Apis mellifera, is distributed in different climatic conditions, and each of them is subdivided into more than thirty subspecies and ecotypes. Their sustainability depends on adaptations to the local climate conditions. The VG gene is involved in the development, reproduction, labor division, and caste differentiation of honey bees. We found the nucleotide sequences of the VG gene reflect the adaptation of honey bees to the local climate conditions. The VG gene sequences are acceptable tools to study the sustainability, genetic structure, and adaptation of A. cerana populations and can be applied in conservation genetics of local honey bee subspecies. ABSTRACT: Apis cerana and Apis mellifera are important honey bee species in Asia. A. cerana populations are distributed from a cold, sharply continental climate in the north to a hot, subtropical climate in the south. Due to the Sacbrood virus, almost all A. cerana populations in Asia have declined significantly in recent decades and have recovered over the past five years. This could lead to a shift in the gene pool of local A. cerana populations that could affect their sustainability and adaptation. It was assumed that adaptation of honey bees could be observed by comparative analysis of the sequences of genes involved in development, labor division, and caste differentiation, such as the gene Vitellogenin VG. The VG gene nucleotide sequences were used to assess the genetic structure and signatures of adaptation of local populations of A. cerana from Korea, Russia, Japan, Nepal, and China. A. mellifera samples from India and Poland were used as the outgroup. The signatures of adaptive selection were found in the local population of A. cerana using VG gene sequence analysis based on Jukes–Cantor genetic distances, cluster analysis, dN/dS ratio evaluation, and Tajima’s D neutrality test. Based on analysis of the VG gene sequences, Apis cerana koreana subspecies in the Korean Peninsula were subdivided into three groups in accordance with their geographic localization from north to south. The VG gene sequences are acceptable tools to study the sustainability and adaptation of A. cerana populations.