四种鲤科鱼类和一种(鱼危)科鱼类的银染核型研究

四种鲤科鱼类和一种(鱼危)科鱼类的银染核型研究 STUDIES ON THE SILVER-STAINED KARYOTYPES OF 4 SPECIES IN CYPRINIDAE AND Ⅰ SPECIES IN BAGRIDAE（PISCES） 桂建芳 Gui Jianfang and Zhou Tun 1 first-author 周暾 1 中国科学院水生生物研究所 中国科学院水生生物研究所 采用银染技术,对四种鲤科鱼类和一种（鱼危）科鱼类进行了银染核型的比较研究。结果表明:鲤科鱼类基本的NORs数可能是四个,且定位在st染色体的短臂上,由于染色体重排等机制的作用,从而造成了NORs定位的种间差异,因此携带有NOR的染色体作为核型演化的指标,来探讨鱼类的系统发生是可行的。在鳤鱼和黄颡鱼中,还发现了同源染色体间Ag—NOR带的相对大小异形,并就鱼类NORs的数目多态、结构多态和实际NORs数的判定等问题进行了讨论。 Silver-stained karyotypes of 4 species in Cyprinidae, namely Ctenopharyngodon idellus, Ochetobius elongatus, Cirrhinus molitorella and Gobiobotia longibarba meridionalis, and 1 species in Bagridae, Pseudobagrus fulvidroeo, were studied. Both the numbers of Ag-stained nucleoli per interphase nucleus and NOR-bearing chromosomes per metaphase varied from 1 to 4 in the 5 species of fishes. We agree to the supposition that the hightest number of Ag-stained nucleoli and NOR-bearing chromosomes observed from nuclei and metaphase corresponds to the actual number of NORs. Thus in the 5 species there are 2 pairs of homologs involved in nucleolar organization. The interspecies resemblances and differences in NORs appear to correspond to the phylogenetic relationship of the 5 species. This suggest that the phenotypes of NORs could prove useful as direct maukers in karyotypic evolution and systematics of Chinese cyprinid fishes. In O. elongatus and P. fulvidraco, consiteat differences between homologues in the size of Ag-NOR bands were found. Heteromorphisms about number of NORs of nuclei and metaphases and about relative size of NORs as well as identification of the actual number of NORs ia fishes have been discussed in the paper. 中国科学院科学基金 1986-01-01 2021-04-01 1