The white-cheeked gibbon is a member of Hylobatidae family, and the four subgenera of gibbons in that family are differentiated according to chromosome number. The term Hylobates means "dweller in trees" and gibbons are especially adapted to an arboreal lifestyle with a special form of locomotion called brachiation, or hand-over-hand swinging. Male and female white-cheeked gibbons range in body length from 457 to 635 mm and the average weight is 5.7kg. Male coloration is mostly black with white fur on the cheeks and a pronounced crest of fur on top of their head. Females do not have white cheek fur and their body color is reddish-brown, with a black face. The gibbon is considered a lesser ape and thus provides a good phylogenetic link between the great apes and Old World monkeys. Interestingly, the gibbon species appear to be undergoing karyotype evolution at a relatively accelerated rate, as evidenced by an unusually high level of chromosomal rearrangement when compared to hominoids. The availability of paired BAC end sequence data will enable higher resolution of chromosomal rearrangements among gibbons and other primates.
The subgenus and species name of the white-cheeked gibbon is Nomascus leucogenys. Gibbons are found in the forests of southern China, northwestern Vietnam and northern Laos. The gibbons spend a majority of their time in the forest canopy, foraging on fruits and leaves. It is thought their predators are mainly raptors, since their high canopy existence protects them from felid predators.
The Nomascus leucogenys species will be sequenced in collaboration with the Baylor University College of Medicine Human Genome Sequencing Center (BCM-HGSC). A total of 6x whole genome coverage will be produced from the genome of a wild-born Northern white-cheeked female, named "Asia" and will serve as the gibbons reference genome. Dr. Alan Mootnick, Director of the Gibbon Conservation Center (GCC) in Santa Clarita, California provided the blood for DNA extraction. The sequencing method combined whole genome shotgun plasmid, fosmid and BAC end sequences. The WUGSC and BCM-HGSC will jointly produce a gibbons draft sequence assembly. This preliminary sequence assembly will be released to the public, following an internal quality review. A gibbon BAC Library (CHORI-271) is available from the BACPAC resources center. Funding for sequence characterization of the Nomascus leucogenys genome is being provided by the National Human Genome Research Institute (NHGRI), National Institutes of Health (NIH).