鳊鲂鱼类的染色体核型及DNA含量分析

Karyotype and DNA contents analysis of Parabramis and Megalobrama

为了解我国主要鳊鲂鱼类细胞遗传学特征,用肾细胞体内培养法分析鳊鲂鱼类染色体核型,并首次测定了广东鲂、三角鲂、长春鳊等的DNA含量。结果显示团头鲂核型为2n=24m+20sm+4st,NF=92,DNA含量为2.66 pg;广东鲂核型为2n=26m+18sm+4st,NF=92,DNA含量为2.57 pg;厚颌鲂核型为2n=26m+18sm+4st,NF=92,DNA含量为2.81 pg;三角鲂核型为2n=24m+20sm+4st,NF=92,DNA含量为2.60 pg;长春鳊核型为2n=26m+22sm,NF=96,DNA含量为2.34 pg。鲂属鱼类在进化过程中染色体核型存在着趋同性,与长春鳊核型差异明显。无论是DNA含量还是总臂数(NF)鳊鲂鱼类差异都很显著。此外,按总臂数多少划分,长春鳊为特化类群,鲂属鱼类为较原始类群。这些结果可为鳊鲂鱼类的染色体组操作和基因组学研究提供必要资料。

In order to investigate the cytogenetic characters of Parabramis and Megalobrama, their karyotype polymorphisms were studied through cell culture in vivo. The DNA contents of M. amblycephala and M. amblycephala and P. pekinensis were measured for the first time. The karyotype of M. amblycephala is 2n = 24m ＋20sm ＋4st, NF =92, DNA content is 2.66 pg. The karyotype of M. hoffmanni is 2n =26m ＋ 18sm ＋ 4st, NF =92, DNA content is 2.57 pg. The karyotype of M. pellegrini is 2n = 26m ＋ 18sm ＋4st, NF = 92, DNA content is 2.81 pg. The karyotype of M. amblycephala is 2n = 24m ＋ 20sin ＋ 4st, NF = 92, DNA content is 2.60 pg. The karyotype of P. pekinensis is 2n = 26m ＋ 22sin, NF = 96, DNA content is 2.34 pg. The chromosomal karyotypes of Megalobrama genus had convergence during evolution and obviously different from that of P. pekinensis. Both DNA content and fundamental arm number （NF） are significantly different between Parabramis and Megalobrama. In terms of the fundamental arm number （NF） , the P. pekinensis should belong to specialization group, while Megalobrama species belong to primitive classification. Collectively, our results could provide essential data for chromosome set manipulation and genome research of Parabramis and Megalobrama.