FUT1基因新cSNPs的鉴别及其对仔猪抗大肠杆菌F18侵染的影响

 【目的】鉴别影响中国地方猪种仔猪抗水肿与腹泻病的关键基因位点。【方法】采用比较测序法对位置候选基因a1-岩藻糖转移酶基因（FUT1）进行cSNPs搜寻、鉴别，使用PCR-SSCP在10个中、西方猪种共计539个样本中开展SNPs遗传多态性检测；采用小肠上皮细胞体外显微黏附实验在白色杜洛克×二花脸资源家系的479个F2代个体中开展大肠杆菌F18ab黏附表型测定；使用SAS软件包分析SNPs基因型与黏附表型间的相关性。【结果】在FUT1基因中鉴别到两个新的cSNPs位点（M229C/T和M714T/C），其中M714T/C为同义突变，M229C/T引起亮氨酸转变为苯丙氨酸；遗传多态性分析表明FUT1 M229C/T等位基因频率在中国地方猪群与西方商业猪群间差异显著而在中国地方猪群间差异不显著；在白色杜洛克×二花脸资源群体中，进一步对FUT1 M229C/T位点分析其与黏附表型的相关性，结果显示FUT1 M229C/T基因型与黏附表型之间呈显著相关（P<0.05）。【结论】FUT1 M229C/T位点可能是决定中国地方猪水肿与腹泻病的变异位点，该位点在中国地方猪抗水肿与腹泻病选育中具有重要潜在的应用价值。

A Novel Coding Variant in the FUT1 Gene and Its Effects on the Resistance to Escherichia coli F 18 Infection in Piglets

【Objective】The aim of this study was to identify the causal mutation determining susceptibility to diarrhoea and oedema disease in piglets of Chinese indigenous pig breeds. 【Method】In the present study, comparative sequencing was used to identify single nucleotide polymorphisms (SNPs) in a positional candidate gene: a1-fucosyltransferase gene (FUT1). The identified SNPs were genotyped by PCR-SSCP in 10 western commercial and Chinese indigenous breeds. The ECF18 adhesion phenotypes were determined in a total of 457 adult pigs from a White Duroc × Erhualian intercross by an in vitro microscopic adhesion assay. The association of the SNP genotypes with in vitro ECF18 adhesion phenotypes was evaluated by SAS software.【Result】Two cSNPs (M229C/T and M714T/C) were identified in the FUT1 gene. M714T/C was a synonymous mutation while M229C/T was a missense mutation leading to a transition of leucine into phenylalanine. Significant difference in allele frequencies of M229C/Twas observed between Chinese indigenous and western commercial pig breeds, but not among Chinese local breeds. The association analysis showed that the M229T/C genotypes had significant association with ECF18 adhesion phenotypes.【Conclusion】The results indicated that M229T/C might be the causal mutation or in linkage disequilibrium with the causative variant determining susceptibility/resistance to ECF18.