中国八种家鼠C—带核型的比较研究

本文对我国大陆八种家鼠的C-带核型进行了比较研究,并将其C-带差异数量化,进行模糊聚类分析,结果表明: 1.八种家鼠的C-带核型相互间存在一定的差异; ①八种家鼠染色体着丝点异染色质在数量上各不相同,按照一定的顺序呈现逐渐减少的趋势。②某些种类出现了插入异染色质、端位异染色质和异染色质短臂。 2.根据八种家鼠C-带核型的不同,结合地理分布等,对八种家鼠的分类地进行了讨论。 3.依据C-带核型的差异,推测八种家鼠的C-带核型进化方向可能是:①着丝点异染色质逐渐减少;②端位异染色质、插入异染色质或异染色质短臂的出现和增加。 4.按照从原始到特化的方向将C-带核型差异数量化,通过模糊聚类分析,得到了八种家鼠的聚类分析分支图,它们可以分为二个大组:斯氏家鼠和环齿鼠为一组,其余种类为另一组。

COMPARATIVE STUDIES ON THE C-BANDED KARYOTYPES OF 8 SPECIES OF GENUS Rattus IN CHINA

This paper deals with the comparicon of C-banding pattorns of all Rattas specics(8 speces) in China. And there are some differences among theis C-banded karyotypes . The cvolution of C-banding patterns of 8 spceics of rats has been studied, and the following tactors maybe facilitate karyotypic variability, loss of centromeric heterochromatin, interstitial heterochromatin, terminal hclcroch-romatin and hcterochromatic arms. Based on the different characteristics of C-banded karyotypes. R, yunn-anensis ,R. sikkimmensis and R. turkcstanicus may be classified into three independent species. Moreover, a cluster dendrogram has been presented in this paper by the fuzzy aggregation. It shows that these 8 species are able to diviele into two groups:R. rattus sladeni R. sikkimensis for the first group and R. fluvipectus, R. yunnancnsis. R. nitidus, R. losca, R. turkestanicus and R, norveyicns for the sccond.