STANDARDIZED KARYOTYPE AND IDIOGRAM OF MEHSANI BUFFALOES, Bubalus bubalis BY CONVENTIONAL STAINING, GTG-BANDING, CBG-BANDING AND AG-NOR BANDING TECHNIQUES

Standardized karyotype and idiogram of the Mehsani buffalo (Bubalus bubalis) at Burirum Livestock Research Station, Thailand, was studied. Blood samples were taken from two male and two female buffaloes. After standard whole blood lymphocytes were cultured at 37 o C for 72 h in the presence of colchicine, the metaphase spreads were prepared on microscopic slides and air-dried. Conventional staining, GTG-banding, CBG-banding and Ag-NOR banding techniques were applied to stain the chromosomes. The results showed that the diploid chromosomes number of Mehsani buffaloes was 2 n =50; the fundamental numbers (NF) were 60 in both male and female. The types of autosomes were four large metacentric, six large submetacentric, eight large telocentric, eight medium telocentric and 22 small telocentric chromosomes. The X chromosome was a large telocentric chromosome and the Y chromosome was a small telocentric chromosome. In GTG-banding, each chromosome pair appeared clearly differentiated. CBG-banding showed dark bands on the centromere of all telocentric chromosomes (autosome pairs 6-24 and the X chromosome) but light band on the others (autosome pairs 1-5 and the Y chromosome). Ag-NOR banding exhibited six position of autosomes (four telocentric and two submetacentric chromosomes) in Mehsani buffaloes. The karyotype formula of Mehsani buffaloes was as follows: 2 n (diploid) 50 = L m 4 + L sm 6 + L t 8 + M t 8 + S t 22 + sex chromosomes.