Alternative promoters of Peg3 with maternal specificity.

Bambarendage P U Perera,Joomyeong Kim

doi:10.1038/srep24438

Abstract

Peg3 (paternally expressed gene 3) is an imprinted gene localized within an evolutionarily conserved 500-kb domain in human chromosome 19q13.4 and mouse proximal chromosome 7. In the current study, we have identified three alternative promoters for mouse Peg3 and one alternative promoter for human PEG3. These alternative promoters are localized within the 200-kb upstream region of human and mouse PEG3, which is well conserved and thus predicted to harbor several cis-regulatory elements for the PEG3 domain. In the mouse, two of these alternative promoters drive maternal-specific expression of Peg3 specifically in the hypothalamus of the adult brain, while the remaining third promoter drives bi-allelic expression of Peg3 with a paternal bias only in the neonatal-stage brain. In human, an alternative transcript is also detected at relatively very low levels in adult brain and placenta. Overall, the identification of alternative promoters in both mouse and human models suggests that these alternative promoters may be functionally selected features for the PEG3 imprinted domain during mammalian evolution.

Highlights

Pattern with a strategy involving 5′ RACE and next generation sequencing (NGS)-based ( Generation Sequencing) deep sequencing experiments
This promoter is functional only from the paternal allele. This 4-kb DMR of Peg[3] was deleted using a floxed allele recently generated in the lab named KO2-Neo
We have identified three alternative promoters for mouse Peg[3] and one alternative promoter for human PEG3

Summary

Introduction

Pattern with a strategy involving 5′ RACE and NGS-based ( Generation Sequencing) deep sequencing experiments. To identify potential alternative 1st exons of Peg[3], a series of 5′ RACE (Rapid Amplification cDNA Ends) experiments were performed using total RNA isolated from the tissues of the two mutant strains and their wild-type littermates (Fig. 2A). The three alternative transcripts of Peg[3] were further characterized in terms of their allele and tissue specificity using RT-PCR experiments (Fig. 3).

Results

Conclusion