Insight Into Pituitary LncRNA and MRNA at Two Estrous Stages in Small Tail Han Sheep With Different Genotypes

The pituitary is a remarkably dynamic organ with roles in hormone (FSH and LH) synthesis and secretion. In animals with the (fecundity Booroola) mutation, the pituitary experiences hormone fluctuations during the follicular-luteal transition, which is implicated in the expression and regulation of many genes and regulators. Long non-coding RNAs (lncRNAs) are a novel type of regulatory factors for the reproductive process. Nevertheless, the expression patterns of lncRNAs and their roles in mediated follicular development and ovulation remain obscure. Thus, we profiled the pituitary transcriptome during the follicular (F, 45 h after evacuation vaginal sponges) and luteal (L, 216 h after evacuation vaginal sponges) phases in -mutant homozygous (BB) and wild-type (WW) Small Tail Han sheep. We identified 78 differentially expressed genes (DEGs) and 41 differentially expressed lncRNAs (DELs) between BB_F and BB_L, 32 DEGs and 26 DELs between BB_F and WW_F, 16 DEGs and 29 DELs between BB_L and WW_L, and 50 DEGs and 18 DELs between WW_F and WW_L. The results of real-time quantitative PCR (RT-qPCR) correlated well with the transcriptome data. In both the follicular and luteal phases, DEGs (, glutamate ionotropic receptor delta type subunit 2; , ST14 transmembrane serine protease matriptase) were enriched in hormone synthesis, secretion, and action. MSTRG.47470 and MSTRG.101530 were the -regulated elements of (inhibitor of DNA binding 3, HLH protein) and the DEG (inhibitor of DNA binding 3, HLH protein), and (eukaryotic translation elongation factor 2), respectively; these factors might be involved in melatonin and peptide hormone secretion. In the -mediated follicular phase, MSTRG.125392 targeted seizure-related 6 homolog like (), and MSTRG.125394 and MSTRG.83276 targeted the DEG (potassium voltage-gated channel subfamily Q member 3) in , while MSTRG.55861 targeted (FKBP prolyl isomerase 4) in . In the -mediated luteal phase, LOC105613905, MSTRG.81536, and MSTRG.150434 modulated , , , respectively, in . We postulated that the mutation in pituitary tissue elevated the expression of certain genes associated with pituitary development and hormone secretion. Furthermore, this study provides new insights into how the pituitary regulates follicular development and ovulation, illustrated by the effect of the mutation.