【摘要】 本文以鱼类肾细胞为材料,用空气干燥法制备染色体标本,对四种胡子鲇的核型进行了分析和比较。观察到这几种鱼的肾细胞中都存在不同程度的罗伯逊易位和其他染色体易位的现象。在蟾胡子鲇的核型中发现有粒状染色体的存在;在四种鱼中都发现可能是XY性染色体的异型染色体。结果还表明,斑点胡子鲇的核型可能由胡子鲇的核型通过染色体罗伯逊易位进化而来,而蟾胡子鲇的核型则是这四种鱼中最原始的一种。更多还原

【Abstract】 In this paper,an analysis and comparison of four species of catfish,i.e.Clarias fus-cus,C.macrocephalus,C.leather,C.batrachus,are carried out based on the chromosome preparations of kindney cells by air-drying method.The results are shown in the following:Clarias fuscus:2n=56,consisting of 9 pairs of metacetric,12 pairs of submeta-centric,7 pairs of telocentric,AN=98.C.macrocephalus:2n=54,consisting of 12 pairs of metacentric,10 pairs of sub-metacentric 5 pairs of telocentric,AN=98.C.leather:2n=56,consisting of 11 pairs of metacentric,9 pairs of submetacentric,8 pairs of telocentric,AN=96.C.batrachus:2n=100,consisting of 2 pairs of metacentric,3 pairs of submetacentric,39 pairs of telocentric,6 pairs of mini-chromosome,AN=110.Besides,some centromeric fusions and chromosome translocations in varying degrees,as well as a pair of heteromorphic chromosomes which are tentatively considered as sex chromosome X and Y are observed in each species.In view of the comparisons,it is supposed that among the four species,the karyotype of C.batrachus is the most primitive,from which,the various karyotypes of other species in Clarias might arise probably through gross chromosomal rearrangements such as Robertsonian transloca-tion,mini-chromosome loss,etc.更多还原