实验采用植物血凝素、秋水仙碱腹腔注射,肾细胞直接制片法分析了川纹笛鲷luTJAnuS SEbAE染色体核型、Ag-nOrS和C-带。结果表明:1)川纹笛鲷二倍体染色体数2n=48,核型公式为:2n=48T,nf=48;在第1对染色体靠近着丝粒部位有明显的次缢痕。2)染色体经快速银染后,Ag-nOrS的数目在不同细胞中表现出多态性,数目1—4个,2个Ag-nOrS的频率最高(占79%)。在分裂相中,第1对T染色体近着丝粒的次缢痕区均出现2个银染位点(Ag-nOrS阳性),且未见Ag-nOrS的联合现象。3)大多数染色体的着丝粒区显示出1个深浅不同的C-带,在第1对染色体的随体区域分布有大量的结构异染色质,表现C-带强阳性。讨论了鱼类核型演化规律和Ag-nOrS、C-带的发生机制,以及川纹笛鲷的进化地位。Studies on karyotype,Ag-NORs,and C-banding of Lutjanus sebae were performed.The chromosomes were re-ceived from the head kidney by using a method of injecting with PHA and colchicines,air drying,and Giemsa staining.The results were as follows.1) The karyotypic formula of L.sebae was 2n=48t,NF=48.Meanwhile,a pair of chromosomes,with secondary constriction near the centromere,was found on chromosome 1.2) The Ag-NORs polymorphisms were individually specific in this fish.The silver staining pots were 1-4,and the number of Ag-NORs was mainly 2(79%).A pair of nucleolar organizer regions was observed on the secondary constriction of chromosome 1,and no Ag-NORs combination was found.3) Centromeres of most chromosomes were C-bandings positive,and heterochromatin was detected at the satellite zone of chro-mosome 1.Thus,we discussed the evolution of karyotype,the developing mechanism of Ag-NORs,and C-bandings for fish.The phylogenetic condition of L.sebae was evaluated as well.国家自然科学基金项目(30070595);国家“863”计划项目(2006AA10A414
