鲈鲤(Percocypris pingi)染色体核型及C-带分析

鲈鲤(Percocypris pingi)为长江上游特有鱼类及四川省重点保护鱼类,为验证其倍性及丰富其细胞遗传学内容,采用植物性血凝素(PHA)体内注射肾细胞直接制片法研究鲈鲤的核型,采用改进的BSG法研究其C-带.结果显示,鲈鲤的染色体数目为98条,其核型公式为4n=98=42m+30sm+10st+16t,臂数NF=170.本研究发现,鲈鲤有16条端部着丝粒染色体,未发现小染色体及其他异型性染色体.鲈鲤C-带带纹较丰富,显示着丝粒带、端粒带和染色体居间带3种类型的C-带,部分染色体同时含有多种类型的C-带着色,如m2、st4同时含有以上3种C-带带纹类型.鲈鲤染色体异染色质含量高达(58.824±0.034)％.本研究再次确认鲈鲤为四倍体,同时指出其染色体具有一定的“可塑性”,反应出鲈鲤对于地区特化的生境具有较强的适应性.

The Karyotype and C-Banding of Percocypris pingi

Percocypris pingi is one of the endemic fishes in the upper reach of the Yangtze River and is one of the protected fish species in Sichuan Province.In this study,we investigated the ploidy and other cytogenetical characteristics ofP.pingi.The karyotype of the renal tissue ofP.pingi was examined using PHA injection with air-dry method.The C-band of P.pingi was displayed with modified BSG method.The results showed that the number of chromosomes of P.pingi was 98,and the formula could be expressed as 4n=98=42m+30sm+ 10st+ 16t,and the arm number (NF) was 170.Sixteen telocentric chromosome of P.pingi was found in this study although unreported in previous studies.Neither small chromosomes nor other heteromorphic chromosomes were found.All the karyotype had the size of the C-band appeared.The types of C-bands of P.pingi were diverse,including centromeric band,telomere band and intermediate band.Multiple C-bands were found in some chromosomes,for example,all types of C-bands were found in m2 and st4.The level of the heterochromatin was 58.824％±-0.034％.We confirmed once again that P.pingi was a tetraploid fish.Its chromosomes were ‘plastic’ to some extent based on the karyotype and C-bands,indicating that P.pingi might be adaptable to specific habitats in different regions.