Abstract: To determine the DNA methylation status of imprinted genes in the prepubertal porcine testis, we chose the testis tissues of 1, 2 and 3 months old pigs, and detected the methylation levels of eight imprinted porcine genes on the basis of the genome-wide DNA methylation profile of prepubertal porcine testis, using the method of MeDIP-seq. The results demonstrated that DIRAS3, IGF2, IGF2R, MEST, NAP1L5, NNAT, PEG10 and PLAGL1, all these eight imprinted genes showed low methylation levels with “unmethylated” or “partially methylated” status. The methylation levels of NNAT and PLAGL1 promoters increased from one month old (T1) to three months old (T3); the methylation levels of NAP1L5 and IGF2R promoters decreased from T1 to two months old (T2) but increased from T2 to T3; while the methylation levels of DIRAS3, IGF2, MEST and PEG10 promoters increased from T1 to T2 but decreased from T2 to T3. Besides, we only aligned 4 gene bodies from the methylation profile, and the methylation levels of IGF2R and MEST gene bodies decreased from T1 to T3, while the methylation levels of PLAGL1 and PEG10 gene bodies increased from T1 to T2 but decreased from T2 to T3. It can be postulated from the results that these eight imprinted genes may be active during the development of prepubertal porcine testis, and DNA methylation may play a role in regulation of imprinted genes.

Key words: DNA methylation, imprinted genes, testis, pigs, prepuberty