MOLECULAR PHYLOGENETIC STATUS OF THE IRIOMOTE CAT FELIS-IRIOMOTENSIS,INFERRED FROM MITOCHONDRIAL-DNA SEQUENCE-ANALYSIS

To investigate the molecular phylogenetic status of the Iriomote cat F elis iriomotensis, partial sequences of the mitochondrial 12S rRNA gen e (373 bases) and the cytochrome b gene (402 bases) were determined by using the polymerase chain reaction-product direct sequencing techniq ue and then compared with those of seven other feline species. Six Iri omote cats examined in this study showed no intraspecific variation fo r both genes. The sequence comparisons and the molecular phylogenetic trees indicated that the Iriomote cat is very closely related to the l eopard cat Felis bengalensis, which is a widespread species throughout southern and eastern Asia, and that it is reasonable for these two fe lines to be classified to the same genus. Based on sequence data, the Iriomote cat was estimated to have diverged from the leopard cat arrou nd or less than 0.2 million years ago, and this concurs with the previ ously reported geological isolation date of the Ryukyu Arc from the Ch inese continent. Our results suggest that the geographic barrier has l ed the fixation of some unique morphological characters into the Iriom ote cat population while both the Iriomote cat and the leopard cat sti ll retain very close genetic characters.