earticle

영어

Understanding the sophisticated imprinting pattern is the first challenge for deciphering the molecular mechanism of an imprinted gene. However, the determination of imprinted genes, and their methylation status in pigs, remains inefficient at present. Herein, for the first time, we have made an attempt to illustrate the complex imprinting pattern of porcine GNAS complex locus by an efficient strategy using RNA-seq analysis of parthenogenetic fetuses containing no paternal allele, but two maternal alleles. RNA-seq results showed that Nespas, Gnasxl, and Exon 1A genes expressed at extremely lower levels (p<0.05) in parthenogenetic fetuses compared to the normally fertilized fetuses, suggest these three genes are paternally-expressed. Whereas, the expression levels of Gnas were similar in both groups, suggesting biallelic expression of Gnas. The parental-specific expression of these genes was further confirmed by quantitative real-time PCR. Bisulfite sequencing revealed that the maternally derived Nespas promoter was methylated, but the paternal chromosome was not methylated. Our finding provided full-scale imprinting information on porcine GNAS locus for the first time. Furthermore, our study is useful for identify novel imprinted genes, confirm the previously known imprinted genes, and determine imprinting pattern efficiently.