大熊猫染色体晚复制带研究

以培养的大熊猫外周血淋巴细胞为实验材料，在细胞培养终止前４ｈ加入ＢｒｄＵ（终浓度为１０μｇ／ｍｌ培养基），对复制的染色体ＤＮＡ进行ＢｒｄＵ标记。掺入ＢｒｄＵ的染色体经吖啶橙（０．０５％）处理、紫外光照射、Ｇｉｅｍｓａ染色后，可在染色体上获得清晰的复制带纹。根据众多分裂相所显示的不同复制带型，可初步确定大熊猫每一染色体独特的晚复制带纹。在雌性个体的两个Ｘ染色体中，一条Ｘ染色体复制明显落后于另一Ｘ染色体，尤其在迟复制Ｘ染色体长臂近着丝粒区显现出较宽的晚复制带纹。

Studies on Late Replication Bands of Giant Panda ( Ailuropoda melanoleuca ) Chromosomes

Using the cultured giant panda ( Ailuropoda melanoleuca ) lymphocytes as expe rimental material, we carried out the terminal marking on the chromosomes which were in replication by adding BrdU (a final concentration: 10g/ml) about four hours before harvesting the cells. The chromosomes marked by BrdU were proceeded by staining with acridine orange solution (0.05%), irradiated by ultraviolet and counter-stained by Giemsa, we obtained clear chromosomes replication patterns. According to the different replication bands, every chromosome's characteristics in late replication behavior could be identified. In the two X chromosomes of female individual,one X chromosome is obviously much later than the other one. Especially in the large area near centromere on the long arm of late replicating X chromosome. In the male individual, there is also a large area on the long arm of chromosome Y which replicates very late, but the end of long arm of chromosome Y replicates much earlier