Evaluation of two promising genes from the target region of SSC13 with susceptibility towards the ETEC F4ac adhesion in pigs

Abstract

Enterotoxigenic Escherichia coli (ETEC) expressing F4 fimbria is the major pathogenic bacteria causing diarrhoea in neonatal and post-weaned piglets. Based on our previous GWAS results from 301 pigs in a two generation family-based population, two promising candidate genes (HEG1 and ITGB5) from a 0.65 Mb region on pig chromosome 13 for susceptibility to ETEC F4ac infection were investigated for the presence of possible causative mutations. A total of 23 polymorphisms in their coding regions were identified, and two previous uppermost GWAS significant SNPs (ALGA0072075; GenBank NC_010455.4:g.145009857 A > G) were also chosen for genotyping in the three pig breeds. The genotyping data and association analysis results showed that a C to T polymorphism in exon7, and a G to T polymorphism in exon14 of the HEG1 gene significant increased the effects on the ETEC F4ac adhesion traits (p = 2.853E − 11; p = 1.410E − 09). Although the identified polymorphisms were not causal mutations, these results indicate that the HEG1 gene is an important adhesion molecule, and it could serve as a genetic marker for selecting ETEC F4ac-resistant pigs in breeding programmes.

Keywords

• Pig
• Escherichia coli F4ac
• susceptibility
• HEG1