大獭蛤的核型研究

The karyotype of Lutraria maxima Jonas

以担轮幼虫(trochophore)为材料,采用秋水仙素活体预处理-低渗-固定-热滴制片-空气干燥-染色,制作染色体标本;对标本进行观察、计数、显微拍照,再运用数理统计、软件处理对大獭蛤(LutrariamaximaJonas)的染色体数目及核型进行了探讨。结果显示,大獭蛤二倍体的染色体数目为34,其核型公式为2n=20m+12sm+2st,NF=76,未发现有异型和具随体的染色体。另外本研究还分析了大獭蛤与蛤蜊科的其它种类之间的核型异同,为探讨它们之间的亲缘关系提供科学依据。

With larval chromosome as the research material, using the colchicum pretreatment of the living specimen： hypoosmotying - the fixing - hot dropping making - air drying - dyeing, the chromosome specimen was manufactured. Observing,numbering and photographing the specimen,and then using the mathematical statistic, software, Lutraria maxima Jonas chromosome number and karyotype were discussed. The results show that the karyotypic formula of Lutraria maxima Jonas was as follows： 2n =34, 20m ＋ 12sm ＋ 2st, NF = 76. It was shown that there is no isomerism or satellite chromosome. Furthermore, the comparison of karyotype is also made between different species of Mactridae order, so as to lay a theoretic foundation for further researches on their evolutional relationship.