Presence of several tRNA-like sequences in the mitochondrial genome of the bumblebee, Bombus hypocrita sapporoensis (Hymenoptera : Apidae)

摘要

We have sequenced the mitochondrial genome (mitogenome) of the bumblebee, Bombus hypocrita sapporoensis (Hymenoptera: Apidae). The nearly completed circular genome is 15,468-bp long, excluding a region spanning from srRNA, tRNA(Gln) to the A+T-rich region, with regard to the previously published mitogenome of R ignitus. The gene arrangement of R hypocrita mitogenome was identical to the within-generic species, B. ignitus, the tRNAs of which are highly rearranged compared with the positions observed most frequently in insect mitogenome structures. The most unusual feature of the genome is the presence of a number of intergenic spacer sequences which harbor partial tRNA-like sequences capable of forming a clover-leaf secondary structure with the proper anticodons, although the stem regions are not paired off well. Such features appear to be prevalent in hymenopteran species. The ATPase8, ATPase6, ND4L, and ND6 genes, which are adjacent to another PCG at their 3' end, all harbored potential sequences for the formation of a hairpin structure. This may indicate the importance of such structures for the precise cleavage of the mRNA of mature PCGs.