Threatened species of wildlife can become extinct because of several facators. One of the most crucial factors is low genetic diversity, or genetic deterioration. Therefore, continuous monitoring of the genetic qualities of their populations is indispensable to making appropriate conservation plans. We are now assessing the genetic diversity of the Iriomote wild cat (Felis iriomotensis), the Japanese marsh warbler (Megalurus pryeri) and the threespine stickleback (Gasterosteus aculeatus). A hundred Iriomote wild cat live on Iriomote Island, Okinawa Prefecture, southern Japan. Examination of microsatellite markers indicates that their genetic diversity is so low that genetic mal-effects are likely to occur due to inbreeding depression. We are measuring the diversity of the major histocompatibility complex genes, which are associated with the strength of immunocompetence.

Fig.7 Heterozygosity of microsatellite alleles of felids

Fig. 8 Determination of microsatellite alleles. Alleles are the same in length (134bp) in a homozygote, but different in length (134, 140 or 134, 144) in heterozygotes.