The key long non‐coding RNA screening and validation between germinal vesicle and metaphase II of porcine oocyte in vitro maturation

Abstract

Oocyte maturation plays a vitally important role in the reproduction of pigs. However, the roles of messenger RNAs (mRNAs) and long non‐coding RNAs (lncRNAs) in the developmental process of porcine oocyte maturation are still largely unclear. In this study, a transcriptome analysis of germinal vesicle (GV) and metaphase II (MII) of oocytes from Chinese Duroc pigs was performed. A total of 1,753,030 and 2,486 differentially expressed (DE) mRNAs, 22,811 and 9,868 DE lncRNAs were identified between GV and MII stages, respectively. Furthermore, functional enrichment analysis showed that the common DE mRNAs and DE lncRNAs during the process of maturation were mainly involved in biological process and cellular components. Our study provides new insights of the expression changes of mRNAs and lncRNAs during GV and MII stages, which might contribute to the maturation of oocytes. These results greatly improve our understanding of the molecular mechanisms regulating the maturation of oocytes in pigs.

Physiologically relevant miRNAs in mammalian oocytes are rare and highly abundant

“…Porcine oocyte-specific high abundance of ssc-miR-205 could come from unusually high transcription of the miRNA precursor. However, RNA-sequencing from mammalian oocytes [35,36,52–55] does not support unusually high transcription at the ssc-miR-205 locus (Fig. 3A).…”

“…UCSC browser snapshots depicting transcription in selected miRNA loci from selected species. Tracks from small and long RNA-seq analyses of mouse [54,55], bovine [36,53], and porcine oocytes [35,52] were constructed as described in material and methods. The y-scale for small RNAs depicts counts per million (CPM) of mapped 19-32 nt reads.…”

Single‐cell RNA‐seq reveals mRNAs and lncRNAs important for oocytes in vitro matured in pigs

“…Our group has profiled the transcriptome of pig single GV oocyte, which helped us to find that CDC5L is vital to the quality of GV oocytes (Liu, Wang, et al., 2018), and identify molecular pathways mediated by DMBA treatment on porcine oocytes (Yang, Song, et al., 2020). Recent studies on GV and MII oocytes used only bulk RNA‐seq, with limited sample size (Jiao et al., 2020; Wang et al., 2020). To further investigate the underlying molecular network for oocyte maturation and meiosis, we employed a new single‐cell RNA‐seq method, which can detect mRNA and lncRNA with(out) poly(A) tails simultaneously (Ansuper‐seq).…”

“…Recently, bulk RNA‐seq on the development of GV to MII oocytes in vitro cultured in pigs and sheep was carried out, to determine the importance of mRNAs and long non‐coding RNAs (lncRNAs) (Cao et al., 2014; Jiao et al., 2020; Wang et al., 2020). These studies are of limited sample size, and pooled oocytes of heterogeneous origin could mask important genes and molecular pathways.…”

PS48 promotes in vitro maturation and developmental competence of porcine oocytes through activating PI3K/Akt signalling pathway

“…However, the regulating mechanisms of oocytes in vitro maturation (IVM) need to be further improved, and the quality of oocyte maturation in vitro is still inferior to that of oocyte maturation in vivo. Compared with oocytes matured in vivo, the oocytes matured in vitro tend to have such problems as more high precision fertilization rate, low blastocyst formation rate, not fully unified oocyte cytoplasm and nuclei of mature in the current maturation systems (Jiao et al, 2020). Moreover, the mature quality of porcine oocytes has an essential effect on embryo development after in vitro fertilization (IVF), nuclear transfer (NT) and parthenogenetic activation (PA) (Kim et al, 2010).…”