Zhang B, Ren J, Yan X, Huang X, Ji H, Peng Q, Zhang Z, Huang L
Key Laboratory for Animal Biotechnology of Jiangxi Province, Ministry of Agriculture of China, Jiangxi Agricultural University, 330045 Nanchang, China.
Anim Genet. 2008 Jun;39(3):258-66. doi: 10.1111/j.1365-2052.2008.01721.x.
Enterotoxigenic Escherichia coli (ETEC) F4ab and F4ac are major determinants of piglet diarrhoea. The locus for the ETEC F4ab/ac receptor has been mapped to SSC13q41. MUC13 is a transmembrane mucin expressed predominantly in the epithelial surface of the gastrointestinal tract and the MUC13 gene was assigned to SSC13q41, supporting it as a positional candidate gene for the ETEC F4ab/ac receptor. We herein determined the complete 2679-bp cDNA of pig MUC13, and proved that it was most highly expressed in the jejunum and moderately expressed in the trachea, stomach and liver. Furthermore, 13 MUC13 polymorphisms were identified in 19 founder animals of a White Duroc x Erhualian resource population, and a total of 727 F(2) animals with in vitro ETEC F4ab/ac adhesion phenotypes in this population were genotyped for three identified MUC13 polymorphisms including c.576C>T, c.908A>G and c.935A>C. The transmission disequilibrium test showed that the MUC13 alleles and haplotypes were significantly associated with susceptibility/resistance to ETEC F4ab/ac, especially between haplotype [C;G;A] and susceptibility to ETEC F4ac (P = 8.0e-18). Animals inheriting this haplotype were predominantly susceptible to ETEC F4ac (n = 291/303). Moreover, nearly all animals homozygous for haplotype [T;G;C] (n = 39/41) and a majority of those with the [C;A;A]/[T;G;C] haplotype pair (n = 79/88) were resistant to ETEC F4ab. Our results indicated that MUC13 is in strong linkage disequilibrium with the ETEC F4ab/ac receptor locus and provided potential markers for selection of ETEC F4ab/ac-resistant animals in the pig breeding scheme.
产肠毒素大肠杆菌（ETEC）F4ab和F4ac是仔猪腹泻的主要决定因素。ETEC F4ab/ac受体基因座已定位到猪13号染色体q41区域。MUC13是一种主要在胃肠道上皮表面表达的跨膜黏蛋白，且MUC13基因被定位到猪13号染色体q41区域，这支持其作为ETEC F4ab/ac受体的位置候选基因。我们在此确定了猪MUC13完整的2679 bp cDNA，并证明其在空肠中表达最高，在气管、胃和肝脏中中度表达。此外，在一个大白杜洛克×二花脸资源群体的19头奠基动物中鉴定出13个MUC13多态性，并对该群体中总共727头具有体外ETEC F4ab/ac黏附表型的F2代动物进行了3个已鉴定的MUC13多态性的基因分型，包括c.576C>T、c.908A>G和c.935A>C。传递不平衡检验表明，MUC13等位基因和单倍型与对ETEC F4ab/ac的易感性/抗性显著相关，尤其是单倍型[C;G;A]与对ETEC F4ac的易感性之间（P = 8.0×10-18）。继承该单倍型的动物主要对ETEC F4ac易感（n = 291/303）。此外，几乎所有单倍型[T;G;C]纯合的动物（n = 39/41）以及大多数具有[C;A;A]/[T;G;C]单倍型对的动物（n = 79/88）对ETEC F4ab具有抗性。我们的结果表明，MUC13与ETEC F4ab/ac受体基因座处于强连锁不平衡状态，并为猪育种方案中选择抗ETEC F4ab/ac的动物提供了潜在标记。
