中国穿山甲有丝分裂染色体和减数分裂联会复合体（SC）的研究

中国穿山甲（Manis pentadactyla）的细胞遗传学分析表明，染色体数目2n=40。除着丝粒C带外，还有染色体端部C带和插入性C带。两对小的端着丝粒染色体的随体部位有银染核仁组织者（Ag-NORs）。本文对穿山甲核型的多态性以及减数分裂联会复合体的结构，性染色（X，Y）在减数分裂前期的行为进行了分析和讨论。

STUDIES ON THE MITOTIC CHROMOSOMES AND MEIOTIC SYNAPTONEMAL COMPLEXES (SC) OF CHINESE PANGOLIN (Mams pentadactyla)

A new karyotype of Chinese pangolin (Manis pentadactyla) was studied by C-banding, silver staining and analysis of synaptonemal complexes of sper-matocytcs. The karyotype reported in this paper is characterized by a diploid chromosome number of 40, with constitutive heterochromatin on centrimeric, distal and interstitial regions of chromosomes. Ag-NORs, with different activities in cells, were found to be located on chromosomes 18 and 19 respectively. Observations on synaptonemal complex show that the pairing between some areas on X chromosome and Y chromosome, forming loops along the X. Y axes, is later than others, which may imply the existence of nonhomologous pairing and synaptic adjustment in the pairing of sex chromosome of Chinese pangolin. Based on the comparative studies of on karyotypc of the same species in literature and our observations on chromosomes of Chinese pagolin (M. pcnta-dactyla), the chromosome polymorphism and po.ssibile mechanism of the kar-yotypic evolution of M. pentadactyla are also discussed.