Search

The time of puberty onset is crucial for female animal, as it can affect the generation interval, feeding costs and the utilization of animals. However, little is known about the mechanism of hypothalamic lncRNAs (long noncoding RNAs) in regulatory goat puberty onset. Therefore, genome‐wide transcriptome analysis was performed in goats to clarify the roles of hypothalamic lncRNAs and mRNAs in the onset of puberty. In the present study, the co‐expression network of differentially expressed (DE) mRNAs in goat hypothalamus identified FN1 as the hub gene, and ECM‐receptor interaction, Focal adhesion and PI3K‐Akt signalling pathways are involved in puberty. We also observed the crucial hub transcription factors (TCF12, STAT1, STAT2, GATA3 and TEAD4) associated with reproduction and puberty. Then, genetic correlation analysis of DE mRNAs and DE lncRNAs identified the key lncRNAs involved in puberty. This research supplies a resource for transcriptome studies in goat puberty and indicated DE lncRNAs in the ECM‐receptor interaction pathway were novel candidate regulators for genetic studies on female reproduction. [ABSTRACT FROM AUTHOR]

NESFATIN‐1 acts as a neuroendocrine hormone to suppress gonadotropin secretion in the female goldfish and to prevent germinal vesicle breakdown of oocytes in the zebrafish. However, the expression and function of NESFATIN‐1 in meiotic maturation and development of porcine oocytes remains elusive. Genomic structure of porcine NESFATIN‐1 precursor nucleobindin 2 (NUCB2) is first characterized in detail and an evolutionally closer relationship of NESFATIN‐1 between pig and rat is shown by phylogenetic analysis of multiple species. Additionally, immunofluorescence analysis revealed that NESFATIN‐1 is predominantly expressed and localizes on the membrane of both theca cells and granulosa cells, but not expressed in oocytes. Real‐time quantitative polymerase chain reaction showed that the abundance of NESFATIN‐1 transcripts in granulosa cells progressively decreases during the developmental transition from small follicles to large follicles. Correspondingly, NESFATIN‐1 could significantly enhance both the cleavage and blastocyst rate of parthenogenetically activated oocytes from small follicles (p < 0.05), whereas it did not affect meiotic maturation and development of oocytes from large follicles. Interestingly, we found that NESFATIN‐1 significantly improves meiotic maturation of oocytes cultured in chemically defined medium in the absence of pyruvate compared with the control group (p < 0.05), suggesting that the NESFATIN‐1 as a substitute for pyruvate exerts beneficial effects on porcine oocyte maturation. In conclusion, these results demonstrate that NESFATIN‐1 facilitates both meiotic maturation and development of porcine oocytes. [ABSTRACT FROM AUTHOR]

Contents: Epigenetics plays an important role in controlling female puberty. Both DNA methylation and long non‐coding RNAs (lncRNA) regulate the initiation of puberty by affecting the expression of genes related to puberty. While recent studies have indicated that DNA methylation of lncRNA represses the expression of lncRNA, its role in regulating puberty remains unclear. To explore the mechanism between DNA methylation and lncRNAs during puberty onset, we performed whole‐genome bisulphite sequencing (WGBS) and RNA‐sequencing (RNA‐seq). We found that DNA methylation was inversely correlated to gene expression levels during puberty. Methylation levels gradually decreased near the transcription initiation site and were present at high levels in the exon, intron and 3′ untranslated regions. In the promoter, lncRNA expression was negatively related to DNA methylation. We reported hypermethylation in the gene body and downstream of the lncRNA compared with upstream regions. In GO and KEGG analyses, we found enriched target genes of lncRNA, XLOC_960044 and XLOC_767346. During puberty, methylation of these genes increased while expression decreased. Our study indicates that DNA methylation of the promoter is negatively correlated with lncRNA during puberty onset, and methylation regulates the initiation of puberty via lncRNA, which provides new insight into the epigenetic mechanism of puberty onset. [ABSTRACT FROM AUTHOR]

This study was designed to explore the effect of active immunization against maltose binding protein-gonadotropin releasing hormone I hexamer ( MBP- GnRH-I6) on the reproductive function in cats. Each immunized cat was administered twice intramuscularly in the neck at 16 and 20 weeks old. The concentrations of the testosterone and estradiol and the level of anti- GnRH- I antibody in the serum were measured by radioimmunoassay and ELISA, respectively. The results showed that the weight and size of testicles and ovaries, and the concentrations of serum testosterone and estradiol in the immunized animals were lower than those of the control cats ( P < 0.05), but that the levels of anti- GnRH- I antibody were significant higher compared to control animals ( P < 0.05). Testicular tissues from the immunized male cats showed that seminiferous tubules were depauperate with the lumen relatively empty and that the differentiation of spermatogonia was not obvious. Tissues from the immunized female cats showed that the ovaries had many primordial follicles and primary follicles, but no secondary follicle was observed. These results showed active immunization against MBP- GnRH-I6 could make the gonads atrophy and reduce the concentrations of gonadal hormones, which suggested that MBP- GnRH-I6 was a very effective immunogen in the cat. [ABSTRACT FROM AUTHOR]

All- trans retinoic acid ( t- RA) is a natural component and representative physiologically active metabolite of vitamin A, having multiple physiologic functions. The objective of this study was to evaluate the effect of t- RA on goat oocyte maturation and cumulus cell apoptosis during in vitro maturation ( IVM). Immature goat cumulus-oocyte complexes ( COCs) were matured in vitro in the absence or presence of t- RA at concentrations of 10 nmol/L, 100 nmol/L and 1000 nmol/L. Oocyte maturation and embryo development were assessed by polar body formation and parthenogenetic activation, respectively. Oocyte survival was checked by Trypan blue staining. Apoptosis of cumulus cells was analyzed by terminal deoxynucleotidyl transferase nick end labeling staining and quantitative real-time PCR. In comparison with the control group, 100 nmol/L and 10 nmol/L t- RA significantly improved goat nuclear oocyte maturation and survival ( P < 0.05). Addition of 1000 nmol/L t- RA improved nuclear maturation ( P < 0.05), but had no effect on survival of goat oocytes. t- RA had no positive effect on goat parthenogenetic embryonic cleavage, blastocyst formation or total cell numbers. However, t- RA inhibits the apoptosis of cumulus cells ( P < 0.01). t- RA treatment up-regulated the expression of B-cell lymphoma 2 ( BCL-2), catalase ( CAT) ( P < 0.05) and down-regulated the expression of Caspase-8 ( P < 0.05). In conclusion, t- RA has positive effects on goat oocyte nuclear maturation and reduces apoptotic cumulus cells during IVM. [ABSTRACT FROM AUTHOR]