兰州鲇染色体组型

Karyotype of Silurus lanzhouensis

本研究的目的在于认识兰州鲇(Silurus lanzhouensis)染色体组特征,为兰州鲇的细胞遗传学和人工育种研究提供基础参考资料。以兰州鲇培养肾细胞为材料,采用空气干燥法制备染色体玻片标本,分析了兰州鲇的染色体组型。兰州鲇的染色体数2n=58,核型公式为2n=20m+18sm+16st+4t,染色体总臂数(NF)为96。通过比较分析认为,兰州鲇在鲇属鱼类中属于较为原始的类群。

This study aimed to understand the chromosome characteristics of Silurus lanzhouensis, therefore providing basic data for cytogenetic and artificial breeding studies of this species. Glass specimens were prepared by utilizing cultured kidney cells of S. lanzhouensis and air-drying technique, and observed under microscope. The chromosomes were classified and grouped by Levan＇s method （1964）. The results show that S. lanzhouensis has 2n = 58 chromosomes; the karyotype formula is 2n = 20m ＋ 18sm ＋ 16st ＋ 4t; the total number of arms （NF） is 96 （Table 1 and Fig. 1）. The chromosomes vary greatly in shape and size （Fig. 1）. Second constriction could only be observed on chromosome 20 （indicated by an arrow in Fig. 1） while no satellite was observed on any chromosome. Compared with the karyotype of other fishes, it is concluded that S. lanzhouensis could be a more ancestral group among fishes of Silurus.