Alongkoad Tanomtong, Sumpars Khunsook, Wiwat Kaensa, and Roungvit Bunjongrat

pp. 539 - 549

Abstract

This research was the first to report a comparative analysis of G-banded chromosome of Assam macaque, Macaca assamensis  (Primate,Cercopithecidae) and relationship to human, Homo sapiens (Primate,Hominidae). Blood samples were taken from two males and two females held captive in Nakhonratchasima Zoo and Songkla Zoo. After the standard whole blood lymphocyte culture at 37ºC for 72 hr in presence of
colchicine, metaphase spreads were performed on microscopic slides and air-dried. G-banding technique was applied to stain the chromosomes. The results showed that the number of diploid chromosomes of Assam
macaque was 2n = 42. The type of autosomes are 18 metacentric and 22 submetacentric chromosomes. In addition, a pair of short arm chromosome 13 showed clearly observable satellite chromosome. X-chromo some was the submetacentric and Y chromosome was the smallest telocentric chromosome. We found that chromosome 5, 12, 13, 19 and X had the same G-banding patterns as those of human chromosomes. The short arm of chromosome 13 is similar to the chromosome 22 of human as indicated by G-banding techniques. In addition, the long arm of chromosome 13 is similar to the chromosome 15 of human. These results indicate that the chromosome 13 of the Assam macaque was split into 2 chromosomes. Chromosome 1, 3, 6, 7, 8, 9, 10,11, 14, 17 and 20 are similar to those of human chromosomes. This study suggest that the chromosome 1 is a pericentric inversion of human chromosome 1. Chromosomes 2, 4, 15, 16, 18 and Y are different from those of human chromosomes. These results show the evolutionary relationship between the Assam macaque and human.