Comparative Transcriptomics Reveal Key Sheep (Ovis aries) Hypothalamus LncRNAs that Affect Reproduction

Abstract

The diverse functions of long noncoding RNAs (lncRNAs), which execute their functions mainly through modulating the activities of their target genes, have been have been widely studied for many years (including a number of studies involving lncRNAs in the ovary and uterus). Herein, for the first time, we detect lncRNAs in sheep hypothalami with FecB++ through RNA Sequencing (RNA-Seq) and identify a number of known and novel lncRNAs, with 622 and 809 found to be differentially expressed in polytocous sheep in the follicular phase (PF) vs. monotocous sheep in the follicular phase (MF) and polytocous sheep in the luteal phase (PL) vs. monotocous sheep in the luteal phase (ML), respectively. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed based on the predicted target genes. The most highly enriched GO terms (at the molecular function level) included carbonyl reductase (NADPH), 15-hydroxyprostaglandin dehydrogenase (NADP+), and prostaglandin-E2 9-reductase activity in PF vs. MF, and phosphatidylinositol-3,5-bisphosphate binding in PL vs. ML was associated with sheep fecundity. Interestingly, the phenomena of valine, leucine, and isoleucine degradation in PL vs. ML, and valine, leucine, and isoleucine biosynthesis in PF vs. MF, were present. In addition, the interactome of lncRNA and its targets showed that MSTRG.26777 and its cis-targets ENSOARG00000013744, ENSOARG00000013700, and ENSOARG00000013777, and MSTRG.105228 and its target WNT7A may participate in the sheep reproductive process at the hypothalamus level. Significantly, MSTRG.95128 and its cis-target Forkhead box L1 (FOXG1) were shown to be upregulated in PF vs. MF but downregulated in PL vs. ML. All of these results may be attributed to discoveries of new candidate genes and pathways related to sheep reproduction, and they may provide new views for understanding sheep reproduction without the effects of the FecB mutation.

Comparative Transcriptomics Identify Key Hypothalamic Circular RNAs that Participate in Sheep (Ovis aries) Reproduction

“…First of all, the TaqMan probe method [16] was used to genotype the herds (n = 890) of Small Tail Han sheep (STH sheep), and the identified the STH sheep with the FecB ++ genotype were then divided into a monotocous group (n = 6, litter size ≥ 2) and a polytocous group (n = 6, litter size = 1) based on litter size records (the details of litter size have provided in our previous report [14]). All of the sheep involved in this study were bred at the sheep farm of Tianjin Institute of Animal Sciences under the same conditions and with free access to water and feed.…”

“…Then, reverse transcription was performed using PrimeScript™ RT reagent kit (TaKaRa, dalian, China), followed by the use of SYBR Green qPCR mix (TaKaRa, dalian, China) to conduct real-time quantitative polymerase chain reaction (RT-qPCR) through the Roche Light Cycler ® 480II system (Roche Applied Science, Mannheim, Germany). Finally, the data obtained from RT-qPCR were calculated with the normalization of β-actin (the details of the calculation method have been reported previously [14]).…”

“…Regarding the hypothalamus, some researches have investigated the mechanism by which GnRH controls reproduction. Our previous work demonstrated that the long non-coding RNA MSTRG.26777, MSTRG.105228, and MSTRG.95128 may play important roles in the hypothalamus of sheep with FecB ++ by affecting GnRH activities indirectly or directly [14]. In addition, miRNA-200/429 and miRNA-155, as major components of switch, were found to regulate the production of GnRH by targeting Zeb1 and Cebpb , two repressors of GnRH activating [15].…”

Identification of Prolificacy‐Related Differentially Expressed Proteins from Sheep (Ovis aries) Hypothalamus by Comparative Proteomics

“…For the purpose of estrus synchronization, controlled internal drug releasing (CIDRs) (InterAg Co., Ltd., New Zealand) (progesterone 300 mg) were inserted into the vaginas of those sheep for 12 days, ovulation rate (the number of corpus luteum) of those sheep was determined using the laparoscopy procedure on day six after CIDR removal. According to littering records and ovulation rate, all STH ewes were categorized as being polytocous sheep ( n = 6) and monotocous sheep ( n = 6). All sheep had free access to water and food and were fed and housed at the Tianjin Institute of Animal Sciences, Tianjin.…”

Integrated Hypothalamic Transcriptome Profiling Reveals the Reproductive Roles of mRNAs and miRNAs in Sheep

“…With advances in sequencing, the application of RNA sequencing (RNA-seq) in animals, including sheep (Jiang et al, 2014;Zhang et al, 2019a;Zhang et al, 2019b), mice (Beck et al, 2018), and cattle (Correia et al, 2018), enables integral analysis of the expression profiling of mRNA and miRNAs. Therefore, RNA-seq has been widely used to understand some complex traits.…”