德国镜鲤和不同倍性泥鳅银染核型的比较研究

采用PHA体内二次注射法及快速银染法对德国镜鲤和不同倍性的泥鳅进行银染核型的比较研究。结果表明,德国镜鲤中期分裂相及间期核中呈现出Ag-NORs的数目为1～2个,含有2个Ag-NORs频率最高,分别为80%和56%。二倍体泥鳅中期分裂相及间期核中呈现出Ag-NORs的数目为1～2个,含有2个Ag-NORs频率最高,分别为72%和60%。四倍体泥鳅中期分裂相及间期核中呈现出Ag-NORs的数目为1～4个,中期分裂相中含有3个Ag-NORs,频率最高为36%,间期核中含有2个Ag-NORs,频率最高为40%。德国镜鲤2n=100,核型组成为30m+26sm+30st+14t,NF=156。NOR的染色体在核型中位置和NORs在染色体上的位置是:sm组第8号染色体的短臂末端。二倍体和四倍体泥鳅NOR的染色体在核型中位置和NORs在染色体上的位置均是:m组第1号染色体的短臂末端。研究结果证实德国镜鲤与中国鲤鱼一样,是多倍化后经历二倍化过程演变而来,是二倍化的四倍体,即染色体数目为2n=100。四倍体泥鳅进行加倍后未发生二倍化或在二倍过程中,是遗传四倍体,染色体数目为4n=100。

Comparative study on silver-stained karyotype of German mirror carp and different ploidy loaches, Misgurnus anguillicaudatus

Comparative studies of silver-stained karyotype between German mirror carp and diploid and tetraploid loaches were carried out by two injections of PHA in vivo and silver-stained method.The results showed that the silver staining pots were one to two in metaphases and interphases of German mirror carp and the number of Ag-NORs was mainly two(80% and 56%,respectively).Similar result was obtained in diploid loaches and the corresponding frequency were 72% and 60%,respectively.There were one to four silver staining pots in metaphases and interphases of tetraploid loaches and the number of Ag-NORs was mainly three(36%) in metaphases and two(40%) in interphases.The chromosome number of German mirror carp was shown to be 2n=100 and its karyotypic formula was 30m+26sm+30st+14t(NF=156).NORs of German mirror carp was located on the short arm tips of sm chromosome 8 while NORs of diploid and tetraploid loaches were located on the short arm tips of m chromosome 1.These results demonstrated that Garman mirror carp was the same as the Chinese carp in the process of evolution,and they had evoluted from diploid ancestor by tetraploidization,they were diploidized from tetraploid,the number of chromosomes was 100(2n=100).Tetraploid loach might do not experience diploidization after double from diploid,they might be experiencing the process of diploidization after double from diploid,they were genetic tetraploid,the number of chromosomes was 100(4n=100).