Standardized karyotype and idiogram of Thai's native cattle, Bos indicus (Artiodactyla, Bovidae) by convention staining, G-banding, C-banding and NOR-banding techniques

Cytogenetics of Thai’s native cattle ( Bos indicus ) at Rajamangala University of Technology Isan, Surin Campus, was studied. Blood samples were taken from two males and two females. After standard whole blood lymphocyte culture at 37 O C for 72 hours in presence of colchicine, the metaphase spreads were performed on microscopic slide and air-dried. Cytogenetic techniques including conventional staining, G-, C- and NOR-bandings were applied to the chromosomes. The diploid chromosomes number was 2 n =60, the fundamental numbers (NF) were 61 in male and 62 in female. All autosomes were acrocentric with 18 large, 20 medium and 20 small acrocentric chromosomes. The X chromosome was a large submetacentric and the Y was the smallest acrocentric. From G-banding, each chromosome pair appeared with clearly differentiated. C-banding shown C-positive at centromeric region of all chromosomes. NOR-banding staining for nuclear organizer regions (NORs) showed 6 NORs represented at telomeric end of chromosomes. The karyotype formula of Thai’s native cattle was as follows: 2 n (diploid) 60 = L a 18 +M a 20 +S a 20 + sex chromosomes