Study On The Chromosomal Karyotype Of Bear

Blood samples from 22 bear, 11 males and 11 females, were used to study chromosome karotype, so as to Provide some effective cytogenetics basis for the selection, improvement by crossing and disease diagnosis of bear, Peripheral blood lymphocyte culture was used to prepare chromosome . Methods of tlypsase-EDTA and BSG(Barium hydrxide/Saline/Giemsa)were used for G-banding andC-banding respectively .The results showed as follows:Firstly, the number of diploid chromosomes was in the bear 2n=74, with the karyotype 74, XY and 74, XX for males and females respectively. Thirty six homologous Pairs of chromosomes were autosomes, in which chromosomes, Pairs of 1 to 8 were metacentric.9 to 36 . And X was metacetric, Y chromosome terminal.Secondly, observation to C-bands indicated that positive bands distributed in thecentromeres of all terminal chromosomes, id.all centromeres of chromosomes were densely dyed, but two arms lightly dyed.metacetric chromosome and centromeres of chromosomes X was lightly dyed., Y chromosome was lightly dyed.Thirdly, the anaiysis of G-bands showed that bright and dark bands appeared by turn. In this experiment we find haploid of bear has 96 bars masculine bands It showed different bands.And every Pair of chromosomes had its distinct band, and the longer the chromosomes, the more the number of bands, and the more clear the bands, in addition triploid, tetraploid were observed in somatic cells of the normal bears.