抄録
[Purpose] The long-tailed macaque (Macaca fascicularis) adapts to a wide range of ecological settings: secondary forests, mangroves, urban villages, public parks and temples. It widely deploys Thailand from the lower northern and northeastern regions (Petchabun and Mahasarakham provinces; ca. 17 deg. N) to the southernmost region (Yala province; ca. 6.5 deg. N), encompassing the Isthmus of Kra. It shows, therefore, a wide variation in morphological traits (morphometry and pelage color) and physiological traits (reddening and swelling of sexual skins). From our recent field survey on 27 localities throughout Thailand, although the population of this macaque species seems to have increased, their biodiversity appears to have decreased by human activities. They have been isolated from the conspecific local populations by the habitat destruction and suffered from so-called “genetic pollution” by the released pet macaques. It is, therefore, urgently necessary to assess their biodiversity. We have conducted interdisciplinary field research (see also the oral-presentation by Hamada et al.) since 2001, and here we present results of preliminary genetic analyses.
[Subjects and Methods] We temporarily trapped long-tails at 11 locations from the lower northern and northeastern regions (Petchabun and Mahasarakham provs.) through the southern region (Yala prov.) in Thailand, collected blood and extracted DNA. A partial D-loop mt DNA ca. 680 bp was amplified and sequenced. A genetic distance tree was reconstructed using the neighbour-joining (NJ) technique implemented in PAUP* 4.0b10. Bootstrap branch-supporting values were also calculated. The mt DNA sequences of the Macaca sylvanus and Macaca mulatta originated from India and China were used as an out- and in-group references, respectively.
[Results and Discussion] From a preliminary result of the analysis of 400 bp sequence matrix of partial D-loop mt DNA, the NJ tree of Thai long-tails appears to be solidly monophyletic and clearly separated from the M. sylvanus and M. mulatta. They were clustered into genogroups conforming to their geographical distribution. Genetic distances between them also agreed well with geographic distances. Genetic distances between genogroups are considered to reflect the influence of compartmentalization in their evolution in Thailand, which is shown by the fact that Thai long-tails can be separated into two major groups; north and south of the Isthmus of Kra. In conclusion, the biodiversity of Thai long-tails is firstly produced by the latitudinal variation and secondly by the locality specific selective pressure.
