Genetic Diversity and Population Structure of the Japanese Serow (Capricornis crispus) in Gunma Prefecture Based on Mitochondrial DNA Control Region Sequences.

The Japanese serow, Capricornis crispus, is a species endemic to Japan, residing in the mountainous forests of Honshu, Shikoku, and Kyushu. Gunma Prefecture, situated in central Honshu, is one of its habitats. To evaluate the genetic diversity and interrelationships among local populations in Gunma Prefecture, we examined the mitochondrial DNA control region sequences of 364 individuals. Our analysis, using all accessible Japanese serow sequences, revealed that they can be broadly categorized into four clades, labeled I to VI. Within Gunma Prefecture, we identified 15 distinct haplotypes, which can be classified into three haplogroups: G1, G2, and G3. G1, included in clade I, is associated with those reported in northeastern Honshu. G2, which forms clade IV on its own, is predominantly endemic to Gunma Prefecture, with a frequency of 90% in Showa Village at the western base of Mt. Akagi. In contrast, G3, included in clade V, forms a sister group to the haplotype discovered in the Japanese Alps. The haplotype composition exhibited a stark contrast between the regions on the west and east sides of the Kanto Plain, indicating that the Kanto Plain serves as a dividing line for Japanese serow populations. In Tsumagoi Village, 134 out of 144 animals shared the same haplotype, resulting in extremely low haplotype diversity, as indicated by a significant negative value in neutrality tests. This finding aligns with the observed rapid increase in serow in Tsumagoi.