三个地方鸡种MHCB-LBII基因遗传变异与免疫性状的关联分析

Relationships among immune traits and MHC B-LBII genetic variation in three chicken breeds

旨在研究3个地方鸡品种（汶上芦花鸡、莱芜黑鸡、济宁百日鸡）主要组织相容性复合体（MajorHistocompatibility Complex,MHC）B-LB II基因遗传变异与绵羊红细胞（Sheep red blood cell,SRBC）、禽流感（Avian influenza,AI）和新城疫（Newcastle disease,ND）抗体滴度等免疫性状的关系,揭示不同品种间基因变异与免疫性状的相关性。以300只地方品种鸡为材料,运用直接测序和聚合酶链式反应-单链构象多态性（PCR-SSCP）等技术检测MHC B-L BII基因的序列变异。在3个地方鸡品种中分别发现了19~22个核苷酸变异位点,可导致其中16~18个氨基酸的变异。3个地方鸡种MHC B-L BII基因中分别有7~8个（Single nucleotidepolymorphism,SNP）位点与部分免疫性状存在不同程度的显著相关性。变异位点G97A和T138A在3个品种中均存在,与SRBC、ND、AI抗体滴度均显著相关（P〈0.05）。其中,G97A突变在济宁百日鸡中与ND抗体滴度显著相关（P〈0.05）,在莱芜黑鸡中与SRBC抗体滴度显著相关（P〈0.05）,在汶上芦花鸡中与H9抗体滴度显著相关（P〈0.05）;变异位点T138A在汶上芦花鸡和济宁百日鸡中与H9抗体滴度显著相关（P〈0.05）。研究表明3个地方鸡种的MHC B-LB II基因遗传变异与免疫性状存在显著关联。

We have assessed the relationships between immune trait（antibody titers of Sheep red blood cell,SRBC;Avian influenza,AI;Newcastle disease,ND） and varieties of MHC B-LBII Gene in local chicken breeds（Wenshang Barred chicken,LH;Laiwu Black chicken,LWH;and Jining Bairi chicken,BR）.We selected 300 chickens randomly from the three indigenous chicken populations.The variations of MHC B-L BII gene were detected by directly DNA sequencing and polymerase chain reaction-single strand conformation polymorphism（PCR-SSCP）.The results indicated that there were about 19 22 nucleotide mutations in the three local breeds,which could affect 16 18 amino acid variations.Another results indicated that there was significantly relationship between seven to eight SNPs of the MHC B-LBII region and some immune traits（P0.05 or P0.01）.Both locus G97A and locus T138A were found in the three species,which were significantly related to the antibodies of SRBC,ND and AI antibody titers（P0.05）.Among them,the locus G97A was significantly associated with ND antibody titers（P0.05） in BR chicken,with SRBC antibody titers（P0.05） in LWH chicken,and with H9 antibody titers（P0.05） in LH chicken.Furthermore,locus T138A was significantly associated with H9 antibody titers in BR and LH chickens（P0.05）.All those results suggest relationships among the different varieties of MHC B-LBII and immune traits in the three local breeds.