HBK-SPF鸭MHCI区域微卫星标记分析

Analysis of Microsatellite Markers in MHC I Region of HBK-SPF Duck

禽主要组织相容性复合体是一组紧密连锁高度多态的基因群,与免疫反应或敏感性密切相关,鸭MHC I区域全长36.8 kb,由TAP1、TAP2和5个MHC I拷贝基因(UAA-UEA)组成。HBK-SPF鸭是中国农业科学院哈尔滨兽医研究所培育的无特定病原体种鸭,分为B和Q 2个品系,已封闭繁育了7个世代。本文在鸭MHC I区域筛选了4个微卫星位点,通过单链构象多态性分析和聚合酶链式反应直接测序,发现A位点具有多态性,为(GT)n的重复结构,第6代HBK-B和HBK-Q的31个个体和第7代的140个个体进行聚合酶链式反应,结果直接测序,在重复结构之前的108bp中,发现了4种纯合单倍型和6种杂合单倍型;B位点未得到目的产物;C位点位于MHC I拷贝基因UDA和UEA之间,扩增结果与UAA和UBA之间序列高度同源,无法判断基因型;D位点表现为单态,为(ATA)15的固定重复结构。本研究为进一步研究鸭MHC I基因结构和建立家系提供了依据。

Avian major histocompatibility complex( MHC) gene family is a cluster of closely linked and highly polymorphic gene groups that are closely associated with immune response or sensibility. Duck MHC I region has a length of 36. 8 kb,including TAP1,TAP2 and five MHC I gene copies( UAA ~ UEA). Two strains,B and Q,of the HBK-SPF( specific pathogen free) duck have been bred to the seventh generation in Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences. Four microsatellite loci were screened in the MHC I region and polymorphism was detected through the single-strand conformation polymorphism,the polymerase chain reaction( PCR) and the directly sequencing. The A locus was found to be polymorphic and characterized by the repeat motif of( GT)n. In both the HBK-B and the HBK-Q strains,31 and 140 individuals of the sixth and the seventh generations respectively were detected by the PCR and the directly sequencing,and four homozygous and six heterozygous genotypes were found in the upstream 108 bp sequence of the( GT)n; There were no PCR product at the B locus; PCR product of locus C was highly homologous to the corresponding region between the UAA and the UBA genes,and the genotype of locus C could not be identified; locus D was monomorphic,and characterized by the repeat motif of( ATA)15. This study provides useful data for further research on duck MHC I genome and family establishment.