剑尾鱼和魣鳉的核型及银染带型和C带研究

以肾细胞作材料,采用秋水仙素-低渗-空气干燥法和Howell(1980)的方法(银染),Sumner(1972)的方法(C带),对剑尾鱼(Xiphophorushelleri)和(Belonesoxbelizanus)的核型及银染和C带进行了分析.结果显示:这两种鱼的染色体2n均为48.剑尾鱼的核型公式为2n=6st+42t,NF=48.的核型公式为2n=2m+2sm+6st+38t,NF=52.其染色体经快速银染后表明,两种鱼各有1对NORs,并均在微小染色体的着丝点上.多数染色体的着丝点区均显示出一个深浅不同的C带.

Study on the Karyotype, Ag-NORs and C-banding pattern of Xiphophorus helleri and Belonesox belizanus

Using the cells of kidney as material and colchi-cine-low concentration-air drying method and the method (Ag-NORs) of Howell's (1980) and (C-banding) of Sumner's (1972) to make Chromosome Specimen. This paper firstly makes an analysis of karyotype and Ag-NORs and C-banding of Xiphophorus helleri and Belonesox belizanus. The result shows that these two kinds of tropic freshwater admiring fish's 2n is 48. Karyotype formula of Xiphophorus helleri is 2n=6st+42t,and NF=48. And karyotype formula of Belonesox belizanus is 2n=2m+2sm+6st+38t, and NF=52. After the function of the Ag-NORs,the chromosome indicates that each of them has one pair of NORs,they are on the small chromosome. Most of the macrochromosomes show a prominent centromeric C-banding.