Mechanism Of Leptin On Impaired Ovarian Reserve Function After Cold Exposure In Female Rats

Previous studies have shown that cold exposure can cause disturbance of estrus cycle in female rats. However, whether cold exposure can cause organic pathological damage to the reproductive system of female rats was undefined. Meanwhile there are few reports on the mechanism of decompensation in rat reproductive function after cold exposure. This study aims to further discuss how cold exposure impact female ovarian reserve function in rats. Female rats were randomly divided into control group and cold exposure group. Ovarian reserve function, differential genes in hypothalamus reproductive regulation center or peripheral were evaluated. After cold exposure, ovarian reserve function was impaired, follicle development was abnormal, the number of mature follicles decreased significantly, the key hypothalamic reproductive regulation molecule GnRH decreased significantly, the response of its regulatory receptor NPY-5R was down-regulated, and the peripheral hormone serum leptin, which is closely related to it, decreased significantly. Our results indicate that cold exposure can lead to impaired ovarian function in female rats, resulting from decrease in serum leptin cause by WAT leptin depletion, which can release the inhibitory of NPY in the hypothalamus, and further lead to the down-regulation of GnRH expression, resulting in the whole HPO axis.

Reproductive Regulation of PrRPs in Teleost: The Link Between Feeding and Reproduction

Prolactin-releasing peptide (PrRP), a sort of vital hypothalamic neuropeptide, has been found to exert an enormous function on the food intake of mammals. However, little is known about the functional role of PrRP in teleost. In the present study, two PrRP isoforms and four PrRP receptors were isolated from grass carp. Ligand-receptor selectivity displayed that PrRP1 preferentially binds with PrRP-R1a and PrRP-R1b, while PrRP-R2a and PrRP-R2b were special receptors for PrRP2. Tissue distribution indicated that both PrRPs and PrRP-Rs were highly expressed in the hypothalamus-pituitary-gonad axis and intestine, suggesting a latent function on food intake and reproduction. Using grass carp as a model, we found that food intake could significantly induce hypothalamus PrRP mRNA expression, which suggested that PrRP should be also an anorexigenic peptide in teleost. Interestingly, intraperitoneal (IP) injection of PrRPs could significantly induce serum luteinizing hormone (LH) secretion and pituitary LHβ and GtHα mRNA expression in grass carp. Moreover, using primary culture grass carp pituitary cells as a model, we further found that PrRPs could directly induce pituitary LH secretion and synthesis mediated by AC/PKA, PLC/IP3/PKC, and Ca2+/CaM/CaMK-II pathways. Finally, estrogen treatment of prepubertal fish elicited increases in PrRPs and PrPR receptors expression in primary cultured grass carp hypothalamus cells, which further confirmed that the PrRP/PrRPR system may participate in the neuroendocrine control of fish reproduction. These results, taken together, suggest that PrRPs might act as a coupling factor in feeding metabolism and reproductive activities in teleost.

Identification of Photoperiod-Induced LncRNAs and mRNAs in Pituitary Pars Tuberalis of Sheep

The pituitary pars tuberalis (PT) is the regulating center of seasonal reproduction, which can sense the melatonin signal and eventually cause downstream changes of GnRH secretion through TSHβ. Recently, lncRNAs have been identified in animal reproductive-related tissues, and they play important roles in reproductive regulation. Therefore, in this study, we expect to identify photoperiod-induced lncRNAs and genes in pituitary PT of sheep by comparison of expression profiles between short photoperiod (SP) and long photoperiod (LP). Through RNA-Seq, a total of 55,472 lncRNAs were identified in pituitary PT of Sunite ewes. The number of differentially expressed (DE) genes and lncRNAs between SP and LP increased gradually with the extension of LP (from LP7 to LP42). The notable LP-induced candidate genes included EYA3, TSHB, SIX1, DCT, VMO1, AREG, SUV39H2, and EZH2, and SP-induced genes involved ENSOARG00000012585, CHGA, FOS, SOCS3, and TH. In enriched pathways for DE genes and lncRNA target genes between SP and LP, the reproduction- and circadian-related pathways were highlighted. In addition, the interactome analysis of lncRNAs and their targets implied that MSTRG.209166 and its trans-target TSHB, MSTRG.288068 and its cis-target SIX1, and ENSOARG00000026131 and its cis-target TH might participate in regulation of seasonal reproduction. Together, these results will help to determine important photoperiod-induced lncRNAs and genes and give us some new insights into the epigenetic regulation of seasonal reproduction in sheep.

Vibratory behaviour produces different vibrations patterns in presence of reproductives in a subterranean termite species

Vibratory behaviours are widespread in social insects, but the produced vibrations remain poorly explored. Communication using vibrations is an efficient way to transmit information in subterranean environments where visual and odorant signals are less efficient. In termites, different vibratory behaviours are performed in different contexts like reproductive regulation and alarm signalling, but only few studies explored the structure of the produced vibrations (i.e., duration, number of pulses, amplitude). Here, we described several types of vibrations produced by a vibratory behaviour widespread in termites (body-shaking), which can be transmitted through the substrate and detected by other colony members. We analysed the structures of the emitted vibrations and the occurrence of the body-shaking events in presence/absence of reproductives and/or in presence/absence of a stress stimuli (flashlight) in the subterranean termite Reticulitermes flavipes. Interestingly, only the presence of the reproductives did influence the number of pulses and the duration of the emitted vibrations. Moreover, the first part of the emitted vibrations seems to be enough to encode reproductive information, but other parts might hold other type of information. Body-shaking occurrence did increase in presence of reproductives but only briefly under a flashlight. These results show that vibratory cues are complex in termites and their diversity might encode a plurality of social cues.

The Effects of Adiponectin on Infertile Women Undergoing IVF/ICSI Treatment and on Human Granulosa Cells

Adiponectin, one of the most abundant adipocyte-secreted protein, has been involved in female reproductive regulation. This study aimed to 1) compare serum adiponectin levels in various phases of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment including Phase I (the beginning of gonadotropin stimulation), Phase II (around 8 days after gonadotropin stimulation), and Phase III (on the day of ovum pick-up) between success and unsuccess subjects; 2) compare follicular fluid (FF) adiponectin levels between success and unsuccess groups; 3) compare serum adiponectin levels among different phases of IVF/ICSI treatment in success and unsuccess groups; 4) compare the levels of adiponectin between serum and FF; and 5) investigate the effects of adiponectin on mRNA expressions of follicle stimulating hormone receptor (FSHR) and CYP19A1 (aromatase) in human granulosa-like tumor cell line (KGN) (n=3). In the human study, recruited participants (n=30) with age of 26-40 years were enrolled between April 2018 - May 2019. Blood samples were collected at Phases I, II, and III while FF samples were collected at Phase III. Adiponectin levels were comparable between success and unsuccess subjects in both serum (all phases) and FF (Phase III). Furthermore, serum adiponectin levels were comparable among Phase I, II, and III in success and unsuccess groups. In Phase III, serum adiponectin showed positive correlations with serum adiponectin in Phase I and II and serum FSH in Phase I. Interestingly, adiponectin levels in FF were significantly lower than serum at Phase III in unsuccessful pregnancies but were comparable in successful pregnancies. Moreover, FF adiponectin had a negative correlation with serum LH at Phase III in success subjects. In the KGN cell study, adiponectin had no effects on FSHR and CYP19A1 (aromatase) mRNA expression compared with control. In conclusion, high adiponectin levels in serum compared to FF might contribute to unsuccessful IVF/ICSI treatment.

Comparison of Gonadal Transcriptomes Uncovers Reproduction-Related Genes with Sexually Dimorphic Expression Patterns in Diodon hystrix

Diodon hystrix is a new and emerging aquaculture species in south China. However, due to the lack of understanding of reproductive regulation, the management of breeding and reproduction under captivity remains a barrier for the commercial aquaculture of D. hystrix. More genetic information is needed to identify genes critical for gonadal development. Here, the first gonadal transcriptomes of D. hystrix were analyzed and 151.89 million clean reads were generated. All reads were assembled into 57,077 unigenes, and 24,574 could be annotated. By comparing the gonad transcriptomes, 11,487 differentially expressed genes were obtained, of which 4599 were upregulated and 6888 were downregulated in the ovaries. Using enrichment analyses, many functional pathways were found to be associated with reproduction regulation. A set of sex-biased genes putatively involved in gonad development and gametogenesis were identified and their sexually dimorphic expression patterns were characterized. The detailed transcriptomic data provide a useful resource for further research on D. hystrix reproductive manipulation.

Orexin A promotes progesterone secretion in luteinized granulose cells of Mongolian Ovis aries ovary by PRRT2 and ABCG1 genes

Summary To study the role of orexin A in the reproductive regulation of Mongolian sheep, ovine ovarian granulosa cells were cultured in vitro. The cells were divided into groups after luteinization, the experimental group was given orexin A and the transcriptome was sequenced together with that of the control group. The different genes related to reproduction were screened out. qRT-PCR, western blot and enzyme-linked immunosorbent assay (ELISA) were used to verify the selected genes and detect the effect on progesterone secretion. In total, 123 differentially expressed genes were obtained by sequencing. Six genes with high expression related to reproduction (PRRT2, ABCG1, SOX4, TBX3, ID1 and ATP8) were screened. The results of qRT-PCR were consistent with those of sequencing; western blot and ELISA were used to verify the protein levels of steroidogenic acute regulatory protein (StAR) and its related PRRT2 and ABCG1, and to detect their effect on progesterone secretion. Validation results were consistent with those of qRT-PCR and sequencing. The experimental group was given orexin A and compared with the control group. Expression of PRRT2 protein was significantly increased (P < 0.05), ABCG1 protein expression was significantly decreased (P < 0.05), StAR expression was significantly increased (P < 0.05), and progesterone secretion was significantly increased (P < 0.05). The results showed that orexin A promoted the expression of StAR by upregulating PRRT2 and downregulating ABCG1, therefore affecting secretion of progesterone. Gene expression characteristics of orexin A affecting progesterone secretion were preliminarily explored; this study provides a theoretical basis for further study on signalling pathways and reproductive regulation in Mongolian sheep.