Identification of Tissue Expression Characteristics of Pig ALKBH5 and Its Association with Pathogenic Microbial Infection

N 6 -methyladenosine (m 6 A) as a reversible RNA modification has become a new direction and hotspot of RNA epigenetics research in the field of pig genetic breeding. However, the relationship between the m 6 A demethylase ALKBH5 and porcine growth and development as well as pathogenic microbial infection still remains unknown. Here, the expression levels of ALKBH5 in tissues of Meishan pigs at different stages from birth to adulthood were detected by qPCR. Then, we analyzed the expression change of ALKBH5 protein in IPEC-J2 cells after pathogenic infection (PEDV, TGEV, PCV2 and E. coli F18). Results showed that ALKBH5 was expressed in different tissues of Meishan pigs. The expression levels were high in spleen, lung and intestinal tissues (duodenum, jejunum and ileum). Besides, similar expression patterns were observed in specific tissues at different developmental stages. In addition, the expressions of ALKBH5 in the intestinal tissues (duodenum, jejunum and ileum) were significantly lower in the adult stage than in the birth and juvenile stages ( P < 0.05). ALKBH5 protein was significantly up-regulated in IPEC-J2 cells with PEDV or PCV2 infection, but not TGEV. After E. coli F18 infection, the expressions of ALKBH5 mRNA and protein were both significantly down-regulated. Our findings indicated that ALKBH5 expression is closely related to the intestinal resistance to pathogenic infection in piglets. Therefore, it is necessary to further verify the function and mechanism of ALKBH5 gene at the cellular and individual levels in the future, in order to identify it as an important candidate marker for pig disease resistance breeding.