Long non‐coding MEG3 is a marker for skeletal muscle development and meat production traits in pigs

Abstract

Long non-coding RNA maternally expressed gene 3 (lncRNA MEG3) plays an important role in mammalian muscle development. Our previous transcriptome study showed that lncRNA MEG3 is differentially expressed during postnatal skeletal muscle development in pigs. The objective of the present study was to analyse the role of lncRNA MEG3 in prenatal and postnatal skeletal muscle development and investigate the association of MEG3 with meat production traits in pigs. We investigated the sequence conservation and temporal-spatial expression of lncRNA MEG3 and identified its core promoter and single nucleotide polymorphisms (SNPs). Our results show that MEG3 is conserved among pig, human and mouse and is expressed in a tissue-specific manner with high expression levels in kidney and leg and dorsal muscles. In addition, MEG3 is more abundant in prenatal muscle compared to postnatal muscle, and its expression peaks at gestational day 60. Notably, we observed almost no expression 40 days after birth. The core promoter of MEG3 is located upstream of the transcription initiation site between À447 and À40 bp. In our SNP linkage disequilibrium and association analyses, four of the 10 potential polymorphism sites were found to be associated with corrected back fat thickness and age to reach 100 kg (rs325797437, rs344501106, rs81286029 and rs318656749). In addition, three haplotypes were found to be associated with differences in corrected age to reach 100 kg (AAAT, AAAT/GGGC, GAAT/GGGC). Our results indicate that MEG3 regulates skeletal muscle development and is a candidate gene for improving meat production traits in pigs.

Expression Levels of Long Non-Coding RNAs Change in Models of Altered Muscle Activity and Muscle Mass

“…Intriguingly, our data showed that the expression levels of Gtl2 and IG-DMR were increased in two muscle hypertrophy models and were decreased in multiple muscle atrophy models. We and others previously found that the expression levels of lncRNAs at this locus are gradually decreased during muscle growth and aging in mice and pigs [36,[69][70][71]. It is of note that the level of DUM1 expression, which was correlated with the skeletal muscle mass in this study, also gradually decreased during muscle growth and aging in mice [29].…”

LncRNA‐MEG3 promotes bovine myoblast differentiation by sponging miR‐135

“…Longissimus dorsal muscles of embryonic pigs (Yu et al, 2018). Similar to the tissue expressions of postnatal Day 160 in Large White pigs, lncRNA-MEG3 was also highly expressed in skeletal muscle and showing lncRNA-MEG3 was conserved and expressed in many tissues in human (Zhang et al, 2010).…”

NORFA, long intergenic noncoding RNA, maintains sow fertility by inhibiting granulosa cell death

“…Here we identified, for the first time to our knowledge, a sow prolificacy-associated variant, 19-bp duplication in the promoter region of lincRNA NORFA. In domestic animals, only a few lncRNA variants associated with important economic traits were found, including variants rs325797437, rs344501106, rs81286029, and rs318656749 in lncRNA MEG3 associated with porcine meat production traits 62 , a variant g.1263T>A in lncRNA ADNCR associated with bovine growth traits 63 , and a variant in lincRNA GDNF-AS associated with canine insensitivity to pain 64 . Overall, based on the distribution of the 19-bp duplication in pig breeds with different fertility and the expression levels of NORFA in granulosa cells from individuals with different genotypes, we identified for the first time that a candidate lincRNA for sow prolificacy, providing insights into the molecular mechanism of the high prolificacy of Erhualian pigs.…”