Abstract: This study aimed to investigate the relationship between the expression level of porcine m⁶A methylases WTAP and resistance to E. coli infection. In this study, the small intestine tissues of 35-day-old Sutai piglets (Sus scrofa) were collected from 4 individuals of E. coli resistant-and sensitive-type. RT-qPCR was used to detect the expression level of WTAP in the duodenum, jejunum of E. coli resistant-and sensitive-individuals. The mRNA expression level of the WTAP gene in intestinal epithelial cells (IPEC-J2) was detected respectively after Escherichia coli F18ab and F18ac stimulation and lipopolysaccharide (LPS) induction. At the same time, the interference vectors of the WTAP gene were constructed and transfected into IPEC-J2 cells, and the effect of gene silencing on the adhesion ability of E. coli was detected by pili protein detection, colony count and indirect immunofluorescence assay. Results showed that the expression level of the WTAP gene in duodenum and jejunum of resistant individuals were significantly higher than that of sensitive individuals (P<0.01). After F18ab and F18ac stimulation, the expression level of the WTAP gene was significantly decreased, which was consistent with the results after 6 h LPS induction (P<0.01). Meanwhile silencing the WTAP gene could significantly increase the adhesion ability of E. coli (P<0.01). This study verified that the high expression level of m⁶A methyltransferase WTAP may improve the ability of piglets to resist E. coli infection and laid a foundation for further RNA methylation investigation of the regulatory mechanism of E. coli infection in piglets.

Key words: pig, N⁶-methyladenosine (m⁶A), RNA methylation, WTAP, E. coli