Yan Xue-Ming, Ren Jun, Guo Yuan-Mei, Ding Neng-Shui, Chen Ke-Fei, Gao Jun, Ai Hua-Shui, Chen Cong-Ying, Ma Jun-Wu, Huang Lu-Sheng
Provincial Key Laboratory for Animal Biotechnology, Jiangxi Agricultural University, Nanchang 330045, China.
Yi Chuan Xue Bao. 2003 Sep;30(9):830-4.
Enterotoxigenic Escherichia coli F18(ECF18) is a main pathogen that causes edema disease and post-weaning diarrhoea in piglets, and al-fucosytransferase (FUT1) gene has been identified as a candidate gene for controlling the expression of the receptor for ECF18 bacteria. The genetic variations at position 307 nucleotide in open reading frame of FUT1 gene in 26 pig breeds (total 1458 individuals) from 5 western commercial pig breeds and 21 Chinese native pig breeds were investigated by PCR-RFLP. The results showed that the genetic polymorphisms of the FUT1 locus were only detected in 5 western pig breeds and the Chinese Lingao pig breed, 5 western pig breeds possessed 3 different genotypes, and Lingao pig breed had two susceptible genotypes GG and AG, while all the other 20 Chinese native pig breeds only presented the susceptible genotype GG. The results indicated that if M307G-A point mutation in the coding region of FUT1 gene was the key factor determining the expression of the ECF18 receptor, most of Chinese native pig breeds were absent of the genetic background on the resistance to ECF18 bacteria. In this case, it was inferred that the resistance gene to ECF18 might be originated from western pig breeds. In addition, it is of great importance for the conservation of Lingao pig breed as it is the only found Chinese native pig breed possessing resistance M307A allele in FUT1 gene. Generally, compared with exotic pig breeds, Chinese native pig breeds have stronger resistance to edema disease and post-weaning diarrhoea in piglets. The results suggested that further study should be done to identify and characterize putative QTL (quantitative trait locus) or/and the functional gene responsible for the resistance to ECF18 in Chinese native pig breeds.
产肠毒素大肠杆菌F18（ECF18）是引起仔猪水肿病和断奶后腹泻的主要病原菌，α-岩藻糖基转移酶（FUT1）基因已被确定为控制ECF18细菌受体表达的候选基因。采用PCR-RFLP技术对5个西方商用猪品种和21个中国地方猪品种的26个猪种（共1458头个体）FUT1基因开放阅读框第307位核苷酸处的遗传变异进行了研究。结果表明，仅在5个西方猪品种和中国临高猪品种中检测到FUT1位点的遗传多态性，5个西方猪品种有3种不同基因型，临高猪品种有GG和AG两种易感基因型，而其他20个中国地方猪品种均只呈现易感基因型GG。结果表明，如果FUT1基因编码区的M307G-A点突变是决定ECF18受体表达的关键因素，那么大多数中国地方猪品种缺乏对ECF18细菌的抗性遗传背景。据此推断，ECF18抗性基因可能起源于西方猪品种。此外，临高猪品种作为唯一发现的携带FUT1基因抗性M307A等位基因的中国地方猪品种，其保护具有重要意义。总体而言，与外来猪品种相比，中国地方猪品种对仔猪水肿病和断奶后腹泻具有更强的抗性。结果表明，应进一步研究鉴定和表征中国地方猪品种中对ECF18抗性的假定数量性状位点（QTL）或/和功能基因。
