斜带髭鲷(Hapalogenys nitens)厦门养殖群体的染色体核型分析

Karyotypes of Cultured Hapalogenys nitens from Xiamen Stock

采用尾静脉抽血法对斜带髭鲷厦门网箱养殖群体的染色体核型进行了研究,结果显示其核型公式为2n=46=4m+8sm+6st+28t,染色体总臂数NF=58,与喻子牛等对青岛近海斜带髭鲷的研究结果存在差异.通过对比发现厦门斜带髭鲷染色体2倍体数2n=46比青岛的少1对,但大型中部着丝点染色体数目又比青岛海域群体多出一对.从而推断斜带髭鲷厦门网箱养殖群体的染色体核型2n=46=4m+8sm+6st+28t可能是从核型2n=48=2m+8sm+2st+36t通过一对非同源的端部着丝点染色体经罗伯逊易位,着丝点融合形成了一中部着丝点染色体而形成的,进而造成斜带髭鲷不同地理种群间染色体的多态现象.

The karyotypes of cultured Hapalogenys nitens from Xiamen stock were examined from the renal tissue.The number of chromosomes is 2n=46,which include two pair of mid-centromere chromosome,four pair of sub-mid dle-centromere chromosome,three pair of sub-top-centromere chromosome and twenty-eight top-centromere chromosome.It differs from the usual number of chromosomes of saltwater fish,which is 2n=48. The karyotypic formulae is:2n=46=4m+8sm+6st+28t,which was different from the result of Qingdao coastal water population:2n=48=2m+8sm+2st+36t.The number of diploid chromosomes of Xiamen stock cultured population was one pair less than Qingdao coastal water population,but the number of large mid-centromere chromosome of Xiamen population was one pair more than the other one.One of the reasons for this different might be the polymorphism.It might be that the centromeres of one couple of dis-homologous top-centromere chromosome of the Qingdao coastal water population amalgamated into one midcentromere chromosome,and the karyotypic formulae which is:2n=48=2m+8sm+2st+36t turned into 2n=46=4m+8sm+6st+28t,and polymorphism came into being between the two different groups of Hapalogenys nitens.The number of sub-top-centromere chromosomes and top-centromere chromosomes was more than that of the sub-middle-centromere chromosomes and mid-centromere chromosomes,indicating that Hapalogenys nitens was more advanced than most another populations in Perciformes.