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To investigate the leptin related genes expression patterns and their possible function during the gonadal development in fish, the cDNA and genomic sequences of leptin, leptin receptor (leptinR), and leptin receptor overlapping transcript like-1 (leprotl1) were cloned and their expression levels were quantified in the different gonadal development stages of Megalobrama amblycephala. The results showed that the full length cDNA sequences of leptin, leptinR and leprotl1 were 953, 3432 and 1676 bp, coding 168, 1082, and 131 amino acid polypeptides, and the genomic sequences were 1836, 28,528 and 5480 bp, which respectively had 3, 15 and 4 exons, respectively. The phylogenetic analysis revealed that three genes were relatively conserved in fish species. Quantitative real-time PCR results showed that the three genes were ubiquitously expressed in all examined tissues during the different gonadal development stages. The leptin and leptinR took part in the onset of puberty, especially in female M. amblycephala, by increasing the expression levels in brain during the stage I to III of ovary. The expression levels of leptin and leptinR had significant differences between male and female in hypothalamic-pituitary-gonadal (HPG) axis tissues (p < 0.05). The leptinR had the same variation tendency with leptin, but the opposite changes of expression levels were found in leprotl1, which may resist the expression of leptinR for inhibiting the function of leptin in target organ. These findings revealed details about the possible role of these genes in regulating gonadal maturation in fish species. [ABSTRACT FROM AUTHOR]

Introduction Calanus finmarchicus, a highly abundant copepod that is an important primary consumer in North Atlantic ecosystems, has a flexible life history in which copepods in the last juvenile developmental stage (fifth copepodid, C5) may either delay maturation and enter diapause or molt directly into adults. The factors that regulate this developmental plasticity are poorly understood, and few tools have been developed to assess the physiological condition of individual copepods. Results We sampled a cultured population of C. finmarchicus copepods daily throughout the C5 stage and assessed molt stage progression, gonad development and lipid storage. We used highthroughput sequencing to identify genes that were differentially expressed during progression through the molt stage and then used qPCR to profile daily expression of individual genes. Based on expression profiles of twelve genes, samples were statistically clustered into three groups: (1) an early period occurring prior to separation of the cuticle from the epidermis (apolysis) when expression of genes associated with lipid synthesis and transport (FABP and ELOV) and two nuclear receptors (ERR and HR78) was highest, (2) a middle period of rapid change in both gene expression and physiological condition, including local minima and maxima in several nuclear receptors (FTZ-F1, HR38b, and EcR), and (3) a late period when gonads were differentiated and expression of genes associated with molting (Torso-like, HR38a) peaked. The ratio of Torso-like to HR38b strongly differentiated the early and late groups. Conclusions This study provides the first dynamic profiles of gene expression anchored with morphological markers of lipid accumulation, development and gonad maturation throughout a copepod molt cycle. Transcriptomic profiling revealed significant changes over the molt cycle in genes with presumed roles in lipid synthesis, molt regulation and gonad development, suggestive of a coupling of these processes in Calanus finmarchicus. Finally, we identified gene expression profiles that strongly differentiate between early and late development within the C5 copepodid stage. We anticipate that these findings and continued development of robust gene expression biomarkers that distinguish between diapause preparation and continuous development will ultimately enable novel studies of the intrinsic and extrinsic factors that govern diapause initiation in Calanus finmarchicus. [ABSTRACT FROM AUTHOR]

Germ cells of sexually reproducing organisms receive an array of cues from somatic tissues that instruct developmental processes. Although the nature of these signals differs amongst organisms, the importance of germline–soma interactions is a common theme. Recently, peptide hormones from the nervous system have been shown to regulate germ cell development in the planarian Schmidtea mediterranea ; thus, we sought to investigate a second class of hormones with a conserved role in reproduction, the lipophilic hormones. In order to study these signals, we identified a set of putative lipophilic hormone receptors, known as nuclear hormone receptors, and analyzed their functions in reproductive development. We found one gene, nhr-1 , belonging to a small class of functionally uncharacterized lophotrochozoan-specific receptors, to be essential for the development of differentiated germ cells. Upon nhr-1 knockdown, germ cells in the testes and ovaries fail to mature, and remain as undifferentiated germline stem cells. Further analysis revealed that nhr-1 mRNA is expressed in the accessory reproductive organs and is required for their development, suggesting that this transcription factor functions cell non-autonomously in regulating germ cell development. Our studies identify a role for nuclear hormone receptors in planarian reproductive maturation and reinforce the significance of germline–soma interactions in sexual reproduction across metazoans. [ABSTRACT FROM AUTHOR]

GnRH neurons secrete GnRH that controls the development of the reproduction system. Despite many studies, the signals controlling the development of GnRH neurons from its progenitors have not been fully established. To understand the development of GnRH neurons, we examined the development of gnrh3-expressing cells using a transgenic zebrafish line that expresses green fluorescent protein (GFP) and LacZ driven by the gnrh3 promoter. GFP and LacZ expression recapitulated that of gnrh3 in the olfactory region, olfactory bulb and telencephalon. Depletion of gnrh3 by morpholinos led to a reduction of GFP- and gnrh3-expressing cells, while over-expression of gnrh3 mRNA increased the number of these cells. This result indicates a positive feed-forward regulation of gnrh3 cells by gnrh3. The gnrh3 cells were absent in embryos that lack Hedgehog signaling, but their numbers were increased in embryos overexpressing shhb. We manipulated the amounts of kinase that antagonizes the Hedgehog signaling pathway, protein kinase A (PKA), by treating embryos with PKA activator forskolin or by injecting mRNAs encoding its constitutively active catalytic subunit (PKA*) and dominant negative regulatory subunit (PKI) into zebrafish embryos. PKA* misexpression or forskolin treatment decreased GFP cell numbers, while PKI misexpression led to ectopic production of GFP cells. Our data indicate that the Hedgehog-PKA pathway participates in the development of gnrh3-expressing neurons during embryogenesis. [ABSTRACT FROM AUTHOR]

Abstract: Development of the mammalian external genitalia is controlled by a network of signaling molecules and transcription factors. Because FGF signaling plays a central role in this complicated morphogenetic process, we investigated the role of Sprouty genes, which are important intracellular modulators of FGF signaling, during embryonic development of the external genitalia in mice. We found that Sprouty genes are expressed by the urethral epithelium during embryogenesis, and that they have a critical function during urethral canalization and fusion. Development of the genital tubercle (GT), the anlage of the prepuce and glans penis in males and glans clitoris in females, was severely affected in male embryos carrying null alleles of both Spry1 and Spry2. In Spry1 −/−;Spry2 −/− embryos, the internal tubular urethra was absent, and urothelial morphology and organization was abnormal. These effects were due, in part, to elevated levels of epithelial cell proliferation in Spry1 −/−;Spry2 −/− embryos. Despite changes in overall organization, terminal differentiation of the urothelium was not significantly affected. Characterization of the molecular pathways that regulate normal GT development confirmed that deletion of Sprouty genes leads to elevated FGF signaling, whereas levels of signaling in other cascades were largely preserved. Together, these results show that levels of FGF signaling must be tightly regulated during embryonic development of the external genitalia in mice, and that this regulation is mediated in part through the activity of Sprouty gene products. [Copyright &y& Elsevier]

Human Relaxin-2 is best known for its physiological role during pregnancy in the growth and differentiation of the reproductive tract as well as in the renal and systemic hemodynamic changes. This factor can also be involved in the pathophysiology of arterial hypertension and heart failure. Within the last years, Relaxin-2 is already being considered as a promising drug, especially in acute heart failure. RLX030, a recombinant form of Relaxin-2 has shown promising results in the therapy of acute heart failure. However, the role of Relaxin-2 in chronic heart failure has not been detailed investigated yet.We examined the systemic and local expression of Relaxin-2 in patients suffering from chronic heart failure (CHF) undergoing heart transplantation or LVAD implantation (CHF; n=7). Myocardial tissue samples and blood samples of the patients were collected after ethic approval and analyzed via immunohistochemical staining and ELISA analysis, respectively. Homografts and blood samples from by-pass surgery patients with EF>65% served as control group (Control; n=5). Data are expressed as mean±SEM. The statistical differences were determined by unpaired Student t-test and One-Way Anova, as appropriate, using GraphPad Prism 6 software. p<0.05 was considered as statistically significant.The immunohistochemical staining for Relaxin-2 showed a significant higher protein expression in the CHF group compared to the controls (Control 26.49±1.37% vs. CHF 31.35±0.61%; p<0.05). The evaluation of the circulating levels of Relaxin-2 did not show significant differences. However, a trend in elevated Relaxin-2 levels in the CHF group compared to controls was observed (Control 15.32±0.11pg/ml vs. CHF 19.41±3.78pg/ml).Relaxin-2 has been successfully evaluated as a new drug for the treatment of patients with acute heart failure. Our data provide evidence about the promising role of Relaxin-2 in CHF. We have found an up-regulated tissue expression of this protein. Thus, Relaxin-2 seems to provide therapeutic potential of being a novel drug for CHF. [ABSTRACT FROM PUBLISHER]