Abstract
Macaca fascicularis fascicularis (Mff) is the most commonly used animal models in biomedical research, and the knowledge on its genetic diversity within population and genetic divergence will help to gain accurate and precise results in the experiments. The hybridization between different species or subspecies has occurred widely in non-human primates. Due to their wide habitat ranges, Mff has been reported to hybridize either with their parapatric species (M. mulatta) at 15-20°N or with subspecies (M. fascicularis aurea; Mfa) at the vicinity of Isthmus of Kra (10° 15’N). However, the impact of Mff x Mfa hybridization was not evaluated. Therefore, the 38 somatometric dimensions were measured and phylogenetic analyses of mtDNA and Y-chromosome gene (SRY and TSPY) sequences were performed in Mff, Mfa, and hybrids. Mfa had infrazygomatic cheek hair pattern with dark pelage color, slender hand, relative shorter 3rd finger and tail length, while Mff had tranzygomatic cheek hair and lighter pelage color, and the hybrids had mixed-characters. Based on mtDNA and Y-chromosome gene sequences, it denotes the Mfa first originated in Myanmar and migrated in two consecutive routes before hybridizing with Mff. Firstly, Mfa migrated southward along the Andaman seacoast towards southwestern Thailand when the sea level was low during mid- or late-Pleistocene epoch and hybridized with Mff. Secondly, they moved east-northwards across the low altitude area of the Dawna range and hybridized with Mff recently. Based on this preliminary result, hybridization between Mfa and Mff is found in restricted areas in Thailand.
