Promoter characterization and functional association with placenta of porcine MAGEL2.

MAGEL2 (melanoma antigen-like gene 2) is essential for circadian function, metabolism and reproduction in mammals. This study was conducted to investigate transcriptional regulation and functional importance in the placenta of porcine MAGEL2. Quantitative real-time PCR showed that MAGEL2 was highly expressed in porcine hypothalamus, pituitary and placenta (P<0.05). The gene was down-regulated in Meishan but up-regulated in Duroc placentas from 25 days post-coitum (dpc) to 105 dpc (P<0.01). Dual luciferase assay demonstrated that the region -151/+110 had the highest promoter activity. Of the g. -712C>G and g. -708T>C polymorphisms in MAGEL2 promoter, -712C and -708T were observed to be predominant in Large White, Landrace and Duroc populations, while -712G and -708C were predominant in Meishan and Rongchang populations. Moreover, -712C>G and -708T>C had significant effects on MAGEL2 transcription (P<0.05) and placental efficiency (P<0.01). In conclusion, -151/+110 harbors the basal promoter of porcine MAGEL2. The region upstream the basal promoter contains repressive cis-elements. And, MAGEL2 is essential in porcine placenta.