Ancient origin of a dipteromimid mayfly family endemic to the Japanese Islands and its genetic differentiation across tectonic faults

摘要

The Japanese Islands have a high degree of biodiversity, with almost the entire area being designated as a global hotspot of biodiversity'. There is no doubt that many complex factors have contributed to this, particularly the complex history of the geological formation of the Japanese Islands. As such, we have focused on the genetic structure and evolutionary history of dipteromimid mayflies. In this study, 392 specimens from 158 localities were collected and analysed genetically. Phylogenetic analyses were performed using the mitochondrial DNA 16S rRNA and COI regions and the nuclear DNA 28S rRNA and histone H3 regions. We found that these mayflies exhibit a genetic structure that strongly reflects the geological history of the early stages of formation of the Japanese Islands. The degree of genetic differentiation between these two species was extensive. Furthermore, Dipteromimus tipuliformis exhibits an explicit pattern of geographical differentiation. Dipteromimid mayflies have a unique genetic structure that strongly reflects the geohistorical formation of the Japanese Islands. Specifically, it has been shown clearly that they are genetically differentiated across geo-tectonic lines, rather than according to the geographical barriers existing today.