2010 年 75 巻 1 号 p. 15-21
This paper succeeded in discovering the polymorphism of nucleolar organizer regions (NORs) and whole-arm translocation (WAT) between chromosomes 8 and 9 of the lowland agile gibbon (Hylobates agilis unko) in Thailand, after standard whole blood lymphocyte culture and G-banding technique were applied to stain the chromosomes. The results showed that the 2n of H. agilis unko was 44. The type of autosomes were 28 metacentric, 12 submetacentric and 2 acrocentric chromosomes, with the X and Y-chromosome being submetacentric and acrocentric chromosome, respectively. In addition, a pair of the long arms of chromosome 12 showed clearly observable NORs. This is the first report on the polymorphism of NORs in H. agilis unko. The results show a heteromorphism in female with a difference size of NORs of chromosome 12, while in males show an equal size of both chromosome 12 with a homomorphism. We also detected a WAT between chromosomes 8 and 9 in H. agilis unko and found that both male and female chromosomes 8 and 9 were 8c′ (homomorphism, 8c′8c′) and 9′ (homomorphism, 9′9′), respectively, resulting from pericentric inversion and followed by reciprocal translocation.