摘要
采用PHA体内注射肾细胞直接制片法及银染法研究真鲷和黑鲷的核型及Ag—NOR带。指出这两种鱼的核型公式分别为2n=48,2st+46t,NF=48和2n=48,4m+4sm+2st+38t,NF=56。两种鱼的核型中各自唯一的一对亚端部着丝点染色体(st染色体)为典型的具次缢痕的染色体。银染结果显示该次缢痕部位即为银染核仁组织者区域(Ag—Nucleolusorganizer regions NORs),并表现出多态性。同时,在这两种鱼的中期分裂相中普遍观察到了NORs联合现象。此外,还讨论了这两种鱼的亲缘关系和鲷科鱼类中两个类群及其核型的分化问题,认为从细胞遗传学角度看,鲷科鱼类的两个类群在演化过程中是分支进化的。
The karyotypes and Ag -NOR banding of Pagrosomus major and Sparus macro-cephalus are examined from the renal tissue by the PHA- injection - air drying method and the method of silver -staining.Both of the two species have a diploid chromosome number of 48 and their kary-otype formulae are 2st + 46t, NF = 48 and 4m + 4sm + 2st + 38t, NF=56, respectively. There is a pair of chromosomes with secondary constrictions in each species, and the results of silver-staining indicate that the regions of secondary constrictions are nucleo-lus organizer regions (NORs). It is found that the polymorphism of NORs exists in the two species, and the phenomenon of NORs union in metaphase figure is generally ob- served.The phylogenetic relationship of the two types in Sparidae are also discussed in this paper and it is believed that the two types are of divergent evolution in Sparidae.
基金
山东省自然科学基金90D0842
关键词
真鲷
黑鲷
核型
银染
AGNOR染色
Pagrosomus major
Sparus macrocephalus
karyotype
nucleous organizer regions
phylogenetic relationship
