褐牙鲆、夏鲆及其杂交子代核型与DAPI带型分析

Karyotypes and DAPI staining of Paralichthys olivaceus, Paralichthys dentatus and their hybrids

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. dentatus, 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 secondary 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.