Studies On Chromosomal Characteristics In Five Donkey Breeds Of North China

Using the peripheral blood lymphocyte cultural method and dealing the cells with TDR(Thyinidine), MXT(Methotrexate) which can control the cells to divide at the same step, lymphocytes in diakinese including some metaphase cells were achieved. In this paper, chromosomal karyotypic and banding techniques were used to study the chromosomal karyotypes, G-banding, C-banding and high resolution G-banding on GuangLing donkey, GuanZhong donkey, JinNan donkey, JiaMi donkey and QingYang donkey. The sample number is 58. Otherwise, we compare the high resolution G-banding of GuangLing donkey with the GTG-banding of a male donkey reported by Raudsepp in 1999. The results as following:1. The number of diploid chromosomes of the five donkey breeds was 2n=62, (female 62,XX, male 62.XY). In the 30 autosomes pairs, 19 pairs of meta- and submeta-centrics and 11 pairs of acrocentrics. The X chromosomes were all submeta-centric and the Y chromosomes were acrocentric in five breeds.2. The Index of chromosome was measured with professional analysis software of chromosome—UT Image Tool 2.00. According to the Arm Ratio of Chromosomes caculated ahead, the different groups of chromosome were classified. The Relative Length and the Centeromeric Index of Chromosomes were caculated and Multiple Comparisons were performed by SPSS 11.5.3. The comparation between the resolution G-banding of GuangLing donkey and the GTG-banding of a male donkey reported by Raudsepp showed the approximation of their banding patterns.4. Tetraploid and circular chromosomes were observed in this experiment.