麒麟鸡MHC-B区域微卫星位点LEI0258遗传多样性研究

Genetic diversity of Frizzle chicken estimated by the microsatellite LEI0258 in chicken MHC-B region

应用MHC-B区域复合微卫星位点LEI0258研究麒麟鸡的遗传多样性与进化,40份麒麟鸡样品用于等位基因与核苷酸多态性分析与构建中介网络图。共检测到12个等位基因,长度范围为193~489 bp,其中6个为麒麟鸡所特有。观察杂合度、期望杂合度和多态信息含量分别为0.800、0.840和0.811。5个等位基因与11种已知MHC血清型相对应。联合已发表的序列,基于侧翼区变异信息的中介网络图将等位基因分为5个进化枝,麒麟鸡在这些进化枝均有分布,A、B和E进化枝同样存在于红原鸡中。结果表明麒麟鸡保持着较高的遗传多样性水平,提示可能存在多起源,其祖先为红原鸡。

To elucidate polymorphism and evolution of Frizzle chicken,the tandem repeat LEI0258 located within the B region of chicken major histocompatibility complex（ MHC-B region） was applied. Forty samples of Frizzle chicken were used to genotype and sequence for the analysis of allele and nucleotide polymorphism and median-joining network. A total of 12 alleles ranging from 193 bp to 489 bp in 40 samples were found,of which six was novel for Frizzle chicken. The microsatellite LEI0258 showed high levels of polymorphism in this breed,with0. 800,0. 840 and 0. 811 for observed heterozygosity,expected heterozygosity and polymorphic information content,respectively. Five alleles were corresponding to 11 available serotypes. Our results,incorporating with published alleles,were classified into five clusters,based on the SNPs and indels located the sequences flanking the repeats. Frizzle chicken existed in all five clades,and red jungle fowl was also found in the clades A,B and E. Our results suggested that Frizzle chicken maintained high levels of genetic polymorphism in LEI0258,and were origin from red junglefowl with multiple domestication.