褐牙鲆、夏鲆及其杂交子代核型与DAPI带型分析

摘要

为了深入剖析褐牙鲆与夏鲆杂交后代的染色体结构,本研究利用秋水仙素-低渗-空气干燥法制备胚胎染色体和 DAPI (4’,6’-diamidino-2-phenylindole)荧光染色的方法,对褐牙鲆(Paralichthys olivaceus)、夏鲆(Paralichthys dentatus)及其正反交子代胚胎细胞的染色体组型和染色质的分布进行了研究。结果表明,褐牙鲆、夏鲆及其正交子代(褐牙鲆♀×夏鲆♂)染色体组均含有48条端部着丝粒染色体,染色体组型公式均为2n=48t,组内染色体长度分布连续,三者核型相似。反交子代(夏鲆♀×褐牙鲆♂)为46条端部着丝粒染色体,比亲本及正交子代少了两条染色体。DAPI荧光染色显示,褐牙鲆1号染色体中的一条染色体有较明显的次缢痕,夏鲆及正反交子代染色体中未见明显次缢痕。褐牙鲆与正交子代染色体着色较为均一,而夏鲆与反交子代着丝粒区域亮度明显增强。%In order to study the chromosomal structure of the interspecific hybrids between P. olivaceus and P. den-tatus, the chromosomes were obtained from the embryos of Paralichthys olivaceus, Paralichthys dentatus and their reciprocal crosses were prepared using Colchine-hypotonic-air drying methods and stained with gluorescence dye DAPI (4’, 6’-diamidino-2-phenylindole). The results showed that P. olivaceus, P. dentatus and the original hybrids (P. olivaceus♀× P. dentatus♂, Fo) were consisted of 48 telocentromerie chromosomes and their karyotype formula was 2n = 48t, with continuous length intragenomes and similar karyotype. Two chromosomes were missing in the reciprocal hybrids (P. dentatus♀× P. olivaceus♂, Fr). The DAPI banding patterns showed that the distinctive sec-ondary constriction was assigned to one homologue of chromosome 1 in P. olivaceus. The chromosomes were all uniformly stained in P. olivaceus and Fo, except strongly positive staining at the centromere of all chromosomes in P. dentatus and Fr.