Frequencies of mitochondrial DNA haplotypes are characteristically inherited for generations in each population of the wild mulberry silkworm, Bombyx mandarina

摘要

Current populations of the wild mulberry silkworm, Bombyx mandarins Moore (Lepidoptera: Bombycidae), inhabiting Japan were previously shown to be divided in four groups by a genetic variation in the mitochondrial cytochrome c oxidase subunit I (COI) gene. According to the geographic divisions, their phylogeographic natures were suggested to be involved in those of the mulberry trees. This hypothesis was based on a data set of many samples collected from 2008 to 2016, although it is not obvious whether such a compilation is appropriate to depict a snapshot of genetic variation of B. mandarina populations in a wide range. For understanding spatial and temporal stability of the mitochondrial DNA (mtDNA) haplotypes in those populations, we examined thefrequencies of COI haplotypes in current populations. The geographic boundary between the genetic groups 1 and 2 was similarly detected in Kansai as previously found. In addition, the frequency of COI haplotypes were shown to be inherited stably for at least seven generations in a population, despite of neighbor populations carrying quite different haplotypes. These results support the previous picture of the geographic distribution pattern of COI haplotypes in B. mandarina in Japan.