MicroRNAs (miRNAs) play an essential role in the regulation of almost all the biological processes, including melanogenesis. MiR-27a-3p is nearly six times higher in white alpaca skin compared to brown skin, which indicates that miR-27a-3p may be a candidate regulator for melanogenesis. Wnt3a plays an important role in promoting melanoblasts to differentiate into melanocytes and melanogenesis. To confirm the function of miR-27a-3p to melanogenesis in mammals, miR-27a-3p mimic, inhibitor and their negative control were transfected into mouse melanocytes. As a result, miR-27a-3p inhibits melanogenesis by repressing Wnt3a at post-transcriptional level. A significant decrease in Wnt3a luciferase activity was observed in 293T cells co-transfected with the matched luciferase reporter vector and pre-miR-27a. Furthermore, the presence of exogenous miR-27a-3p significantly decreased Wnt3a protein expression rather than mRNA and reduced β-catenin mRNA levels in melanocytes. The over-expression of miR-27a-3p significantly increased the melanin content of melanocytes. However, miR-27a-3p inhibitor performs an opposite effect on melanogenesis. Wnt3a is one target of miR-27a-3p. MiR-27a-3p could inhibit Wnt3a protein amount by post-transcriptional regulation and melanogenesis in mouse melanocytes. Previous studies reported that Wnt3a promoted melanogenensis in mouse melanocytes. Thus, miR-27-3p inhibits melanogenesis by repressing Wnt3a protein expression.

Astragalus membranaceus (AM) is a Chinese traditional herb which has been reported to have broad positive effects on many diseases, including hepatitis, heart disease, diabetes and skin disease. AM can promote cell proliferation, increase the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPx), and inhibit apoptosis by regulating the transcription of proto-oncogenes controlling cell death. While AM is included in some commercially available “testosterone boosting supplements”, studies directly testing ability of AM to modulate testosterone production are lacking. In the present study, we examined the effects of AM on Leydig cell function in vitro. Rat Leydig cells were purified and treated with AM at different concentrations (0 μg/mL, 10 μg/mL, 20 μg/mL, 50 μg/mL, 100 μg/mL and 150 μg/mL) and cell counting-8 (CCK-8) assay, Enzyme-linked immunosorbent assay, quantitative real time PCR and analysis of activities of SOD and GPx were done respectively. Treatment with 100 μg/mL (P < 0.05) and 150 μg/mL AM (P < 0.01) significantly increased Leydig cell numbers. Treatment with AM (20 μg/mL, 50 μg/mL and 100 μg/mL) significantly increased testosterone production (P < 0.01). In addition, increased Leydig cell SOD and GPx activities were observed in response to 20 μg/mL and 50 μg/mL AM treatment (P < 0.01). Furthermore, expression of Bax mRNA was significantly decreased (P < 0.01), and the ratio of Bcl-2/Bax mRNA was significantly increased in response to 20 μg/mL AM in the culture medium (P < 0.05). Results supported a beneficial effect of AM on multiple aspects of rat Leydig cell function in vitro including testosterone production.

N6-methyladenosine (m⁶A) is the most universal post-transcriptional modification of mRNA which may play important roles in verious species. However, the potential roles of m⁶A in the pigmentation of skin are not completely understood. To explore the role of m6A modification in pigmentation of sheep skin, we used MeRIP-seq and RNA-seq to profile the skin transcriptome in black and white coat color (n=3). Our results showed that an average of 7701 m⁶A peaks were obtained for all samples and the average length was 305.89 bp. The GGACUU sequence was the most enrichment motif and shared in black skin and white skin. The m⁶A peaks were mainly enriched in the CDS, 3'UTR and 5'UTR, especially in CDS region near the stop codon of the transcript. 235 significantly differential peaks were found in black skin vs. white skin. The KEGG signaling pathways of downregulated and upregulated m⁶A peaks were mainly enriched in AGE-RAGE signaling pathway in diabetic complications, Viral carcinogenesis, Transcriptional misregulation in cancer, ABC transporters, Basal transcription factors and Thyroid hormone synthesis (P value <0.05). For RNA-seq, 71 differently expressed genes (DEGs) were scanned in black skin vs. white skin. DEGs were significantly enriched in tyrosine metabolism, melanogenesis, neuroactive ligand-receptor interaction pathway (P value <0.05). Combined m⁶A-seq and RNA-seq analysis showed that the hyper-up genes and hypo-up genes were both enriched in ErbB signaling pathway (P value <0.05). In conclusion, it provide a basis for further research into the functions of m⁶A methylation modifications in pigmentation.

Cocaine-and amphetamine regulated transcript (CART) is an endogenous neuropeptide, which is widespread in animals, plays a key role in regulation of follicular atresia in cattle and sheep. Among animal ovaries, CART mRNA was firstly found in the cattle ovaries. CART was localized in the antral follicles oocytes, granulosa and cumulus cells by immunohistochemistry and in situ hybridization. Further research found that secretion of E2 was inhibited in granulosa cells with a certain dose of CART, the effect depends on the stage of cell differentiation, suggesting that CART could play a crucial role in regulating follicle atresia. The objective of this study was to characterize the CART expression model and hormones secretion in vivo and vitro in pig follicle granulosa cells, preliminarily studied whether CART have an effect on granulosa cells proliferation and hormones secretion in multiparous animals such as pigs. The expression levels of CART mRNA in granulosa cells of different follicles were analyzed using qRT-PCR technology. Immunohistochemistry technology was used to localize CART peptide. Granulosa cells were cultured in medium supplemented with different concentrations of CART and FSH for 168 h using Long-term culture system, and observed using a microscope. The concentration of Estradiol (E2) and progesterone (P) in follicular fluids of different test groups were detected by enzyme linked immunosorbent assay (ELISA). Results showed that expression level of CART mRNA was highest in medium follicles, and significantly higher than that in large and small follicles (P < 0.05). Immunohistochemical results showed that CART were expressed both in granulosa cells and theca cells of large follicles, while CART were detected only in theca cells of medium and small follicles. After the granulosa cells were cultured for 168 h, and found that concentrations of E2 increase with concentrations of follicle-stimulating hormone (FSH) increase when the CART concentration was 0 μM. And the concentration of FSH reached 25 ng/mL, the concentration of E2 is greatest. It shows that the production of E2 needs induction of FSH in granulosa cells of pig ovarian follicles. With the increasing of CART concentrations (0.01, 0.1, 1 μM), E2 concentration has a declining trend, when the FSH concentrations were 25 and 50 ng/mL in the medium, respectively. These results suggested that CART plays a role to inhibit granulosa cells proliferation and E2 production, which induced by FSH in porcine ovarian follicular granulosa cells in vitro, but the inhibition effect is not significant. So we hypothesis CART maybe not a main local negative regulatory factor during porcine follicular development, which is different from the single fetal animals.

Objective: The active metabolite of vitamin A, all-trans retinoic acid (ATRA), is involved in the proliferation and differentiation of granulosa cells, and promotes the follicular development, oocyte maturation, and ovulation in mammals. This study aims to investigate the ATRA induced potential long noncoding RNAs (lncRNAs) that regulate the expression of genes associated with granulosa cell proliferation and follicular development.Methods: The lncRNA and mRNA profiles of porcine granulosa cells from ATRA treatment and control group in vitro were constructed through RNA sequencing. Meanwhile, the sequencing data were verified using quantitative polymerase chain reaction (qPCR).Results: A total of 86 differentially expressed lncRNAs and 128 differentially expressed genes (DEGs) were detected in granulosa cells after ATRA treatment. The quantitative real-time PCR (qRT-PCR) results were consistent with the RNA-seq data. Functional annotation analysis revealed that the DEGs were remarkably enriched in ovary function and reproduction which contained FoxO, Hippo, Oocyte meiosis, mammalian target of rapamycin signaling pathway, as well as several pathways associated with hormone regulation like oxytocin signaling pathway and steroid hormone biosynthesis. Moreover, an interaction network of lncRNAs and their cis-target DEGs was constructed, and 7 differentially expressed lncRNAs and 6 cis-target DEGs were enriched in ovarian steroidogenesis and reproduction.Conclusion: These findings expand the lncRNA catalogue and provide a basis for further studies on the mechanism of ATRA-mediated lncRNA regulation of follicular development in pigs.