Comparative analysis of mitochondrial genomes of the honey bee subspecies A. m. caucasica and A. m. carpathica and refinement of their evolutionary lineages

The complete mitochondrial genome sequences of the honey bee subspecies Apis mellifera caucasica and Apis mellifera carpathica were analyzed for the first time. The length of the mitochondrial DNA (mtDNA) sequences of A. m. caucasica and A. m. carpathica are 16,341 and 16,336 bps, respectively. Both sequences contain 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 AT-rich region. The overall composition of the nucleotides in the mtDNA of A. m. caucasica/A. m. carpathica is as follows: A (43.2/43.3%), C (9.5/9.6%), G (5.6/5.5%), and T (41.6/41.6%). Most of the mtDNA genes of both subspecies (ND2, COX1, COX2, ATP8, ATP6, COX3, ND3, ND6, CYTB, and 14 tRNA genes) are located on the heavy strand, and less (ND1, ND4, ND4L, ND5, SrRNA, LrRNA, and 8 tRNA genes) are located on the light strand. Phylogenetic analysis based on the complete mtDNA showed that both subspecies A. m. caucasica and A. m. carpathica are representatives of the C lineage. Thirty-five unique markers (ND5/XbaI and 34 SNPs) were found which enable the differentiation of the honey bee subspecies A. m. caucasica and A. m. carpathica. These genetic markers can contribute to purebred beekeeping and will help to prevent hybridization between these endangered honey bee subspecies in Europe.