摘要
红鲫属于鲤科、鲤亚科、鲫属,染色体数目为2n=100,核型为22m+34sm+22st+22t;鲤属于鲤科、鲤亚科、鲤属,染色体数目为2n=100,核型为22m+34sm+22st+22t。已有研究表明,红鲫(♀)×鲤(♂)杂交第一代(F1)和第二代(F2)为二倍体,F2能产生染色体数不减数的配子,在第三代(F3)中形成四倍体鱼。通对F1和F3进行胚胎染色体制片,在染色体水平上探讨红鲫和鲤远缘杂交的多倍体发生途径及F2产生不减数配子的潜能。结果表明,F1混合胚胎都为二倍性胚胎,没有发现单倍性和多倍性胚胎,但F3混合胚胎中则有染色体数为100,150,200甚至300的染色体分裂相,推测F2生殖细胞发生了一次或多次染色体数加倍,产生了二倍性和更高倍性的配子,它们结合形成了不同倍性的F3胚胎。实验证明双亲基因组大小及核型相似的鲫鲤远缘杂交第一代不发生多倍化,但获得的二倍体杂交后代能产生不减数配子,在F3中产生多倍体鱼。
In the catalog,the red crucian carp（Carassius auratus red var.） with 100 chromsomes belongs to the Cyprinidae,Cyprinidae subfamily,Carassius,with karyotype of 22m＋34sm＋22st＋22t;and the common carp（Cyprinus carpio L.） with 100 chromosomes belongs to the Cyprinidae,Cyprinidae subfamily,Cyprinus,with karyotype of 22m＋34sm＋22st＋22t.The previous studies had indicated that the first（F1）and second generation（F2）of hybrid fish of red crucian carp（♀）×common carp（♂）were diploid,and F2 hybrids could produce unreduced eggs and sperms,which mated each other to form fertile allotetraploid hybrid fish（F3）.In order to explore the pathway of polyploidy occurrence in distant crossing of red crucian caip and common carp and the potential of producing unreduced gametes of F2 hybrids,we studied the chromosome in embryonic cell of F1 and F3 hybrid fish.The result showed that the F1 embryo was diploid,no haploid and polyploidy embryos were observed.While F3 embryos showed 100,150,200 and even 300 chromosomes,and it was inferred that the chromosomes number in germ cells of F2 had doubled one or more times,and the F2 produced diploid and polyploidy gametes,which mated each other to form F3 embryos with different ploidy.Taken together,it was concluded that F1 hybrids which come from crossing parents with similar genome size and karyotype,have not displayed polyploidization,while the diploid hybrid progenies could produce unreduced gametes,they fertilized to form polyploidy fish in F3.The pathway provided important guidance for the study of breeding polyploidy fish by distant crossing.
出处
《水产学报》
CAS
CSCD
北大核心
2011年第9期1369-1373,共5页
Journal of Fisheries of China
基金
国家自然科学基金青年项目(30901100)
国家杰出青年科学基金项目(30725028)
湖南省教育厅科学研究项目(09B060)
国家公益性行业科研专项资金(200903046)
关键词
二倍体杂交鱼
胚胎染色体
不减数配子
远缘杂交
diploid hybrid
chromosomes in embryonic cell
unreduced gamete
distant crossing
