A study on karyotype of the pileated gibbon, Hylobates pileatus (Primates, Hylobatidae), by conventional staining

Cytogenetics of the pileated gibbon (Hylobates pileatus) at Nakhon Ratchasima Zoo, Thailand, was studied. Bloodsamples were taken from two female and two male gibbons. After lymphocyte culture, the mitotic chromosome preparationwas done by hypotonic-fixation-air-drying method and conventional Giemsa s staining. The results show that diploid chromosomenumber was 44 (2n=2x=44), and the fundamental number (NF) were 88 chromosomes in both female and male.The autosomes consist of 12 large metacentric, 6 medium metacentric, 2 medium submetacentric, 2 medium acrocentric, 12small metacentric and 8 small submetacentric chromosomes. In addition, the chromosome 15 showed clearly observablesatellite chromosomes. The X chromosome was a medium submetacentric chromosome and the Y chromosome was a tinyacrocentric chromosome. The karyotype formula for the pileated gibbon is as follows:2n (44) = Lm12+Mm6+Msm2+Ma2+Sm12+Ssm8+sex-chromosomes