부산대학교 도서관

Sumatran orang-utan (Pongo pygmaeus) numbers have plummeted in recent time. Reductions are thought to have been as much as 99% over the last 100 years. Recently numbers are estimated to have dropped from 27000 in 1997 to 3500 a few years ago (Wich et al., 2003). Therefore it is of great importance to get a good idea of the distribution of genetic variability in their last hideouts. For this purpose we collected hairs from sleeping nests, and in addition collected faecal droppings. We sequenced DNA extracted from these samples at a locus of the mtDNA: a 540 bp region of the cytochrome-b gene. Our data set comprises 44 samples of wild individuals, as well as 6 individuals from the local zoo (Medan). We compared these with 2 Bornean samples from PRI (Inuyama) and 4 Bornean sequences and 1 Sumatran sequence from GenBank. The 44 wild samples had been collected along the west coast (n=7), from Ketambe, our main study area in the interior (n=31), and from the surrounding area, including a location across a wide river (n=6). Whole sequences were used to construct a maximum likelihood tree, and to perform additional analyses. Sequences including Sumatra and Borneo were divided into two major clusters, samples originating from Sumatra and those originating from Borneo. The Sumatran cluster was divided into tree strongly supported sub-clusters comprising (a) 7 individuals from Ketambe and surroundings and 2 zoo individuals, all with a single haplotype (b) 2 slightly different zoo individuals, and (c) the remaining 39 individuals of various geographic origin and 7 haplotypes. The results will be discussed.