A comprehensive analysis of spermatozoal RNA elements in idiopathic infertile males undergoing fertility treatment

Current approaches to diagnosing male infertility inadequately assess the complexity of the male gamete. Beyond the paternal haploid genome, spermatozoa also deliver coding and non-coding RNAs to the oocyte. While sperm-borne RNAs have demonstrated potential involvement in embryo development, the underlying mechanisms remain unclear. In this study, 47 sperm samples from normozoospermic males undergoing fertility treatment using donor oocytes were sequenced and analyzed to evaluate associations between sperm RNA elements (exon-sized sequences) and blastocyst progression. A total of 366 RNA elements (REs) were significantly associated with blastocyst rate (padj < 0.05), some of which were linked to genes related to critical developmental processes, including mitotic spindle formation and both ectoderm and mesoderm specification. Of note, 27 RE-associated RNAs are predicted targets of our previously reported list of developmentally significant miRNAs. Inverse RE-miRNA expression patterns were consistent with miRNA-mediated down-regulation. This study provides a comprehensive set of REs which differ by the patient's ability to produce blastocysts. This knowledge can be leveraged to improve clinical screening of male infertility and ultimately reduce time to pregnancy.

Parthenogenetic Stick Insects Exhibit Signatures of Preservation in the Molecular Architecture of Male Reproduction

After the loss of a trait, theory predicts that the molecular machinery underlying its phenotypic expression should decay. Yet, empirical evidence is contrasting. Here, we test the hypotheses that (i) the molecular ground plan of a lost trait could persist due to pleiotropic effects on other traits and (ii) that gene co-expression network architecture could constrain individual gene expression. Our testing ground has been the Bacillus stick insect species complex, which contains close relatives that are either bisexual or parthenogenetic. After the identification of genes expressed in male reproductive tissues in a bisexual species, we investigated their gene co-expression network structure in two parthenogenetic species. We found that gene co-expression within the male gonads was partially preserved in parthenogens. Furthermore, parthenogens did not show relaxed selection on genes upregulated in male gonads in the bisexual species. As these genes were mostly expressed in female gonads, this preservation could be driven by pleiotropic interactions and an ongoing role in female reproduction. Connectivity within the network also played a key role, with highly connected-and more pleiotropic-genes within male gonad also having a gonad-biased expression in parthenogens. Our findings provide novel insight into the mechanisms which could underlie the production of rare males in parthenogenetic lineages; more generally, they provide an example of the cryptic persistence of a lost trait molecular architecture, driven by gene pleiotropy on other traits and within their co-expression network.

In ovo o,p'-DDT exposure induces malformation of reproductive organs and alters the expression of genes controlling sexual differentiation in Japanese quail embryo

In ovo exposure to o,p'-dichloro-diphenyl-trichloroethane (o,p'-DDT) impairs reproduction by inducing malformation of the reproductive organs in birds, although the mechanism remains unclear. Here, we examined the effects of o,p'-DDT on the development of the reproductive organs, the expression of genes controlling sexual differentiation, and the plasma concentrations of testosterone and estradiol in Japanese quail embryos. o,p'-DDT-containing sesame oil was injected into the yolk sac on Embryonic Day (E) 3 at a dose of 500, 2,000, or 8,000 μg per egg. On E15, the reproductive organs were observed; the gonads and Müllerian ducts (MDs) were sampled to measure the mRNA of steroidogenic enzymes, sex steroid receptors, anti-Müllerian hormone (AMH), and AMH receptor 2 (AMHR2); blood samples were collected to assay plasma testosterone and estradiol levels; and the gonads were used for histological analysis. o,p'-DDT dose-dependently increased the prevalence of hypertrophic MDs in females and residual MDs in males. In female MDs, o,p'-DDT dose-dependently decreased estrogen receptor (ER) α, ERβ, and AMHR2 mRNA expression. o,p'-DDT dose-dependently induced left-biased asymmetry of testis size, and ovary-like tissue was found in the left testis after exposure to 8,000 μg per egg o,p'-DDT, although asymmetric gene expression did not occur. o,p'-DDT did not affect ovarian tissue but did decrease 17α-hydroxylase/C17-20 lyase mRNA expression and dose-dependently increased ERβ mRNA expression. o,p'-DDT decreased plasma testosterone concentrations in females. These findings suggest that o,p'-DDT induces hypertrophy of the MDs and ovarian tissue formation in the left testis. Abnormal MD development may be linked to altered gene expression for sensing estrogens and AMH signals.

Potential Implications of Acid-Sensing Ion Channels ASIC2 and ASIC4 in Gonadal Differentiation of Dicentrarchus labrax Subjected to Water Temperature Increase during Gonadal Development

In this study, the expression and implication of acid-sensing ion channels 2 and 4 (ASIC2 and ASIC4) in the gonadal sex differentiation of Dicentrarchus labrax (D. labrax), subjected to increasing water temperatures during gonadal development, were evaluated. Two groups were selected: a control group (CG), in which the average water temperature was maintained at 15 °C and increased to 20 °C in 20 days until weaning; and an experimental group (EG), in which the water temperature was retained at 15 °C for 60 days; thereafter, the temperature was increased daily by 0.5 °C until it reached 20 °C up to the weaning time. Ten fish from the CG and 13 fish from the EG were sampled randomly on the 335th day after hatching (dph). A higher percentage of gonad differentiation in ovaries rather than in testes was observed in the EG compared to the CG (p = 0.01). ASIC2 and ASIC4 were detected for the first time in D. labrax ovaries by indirect immunofluorescence. Both ASIC2 and ASIC4 were expressed in previtellogenic oocytes of ovaries and in scattered cells within some testes, and were most likely intratesticular previtellogenic oocytes in both the CG and EG groups. The CG group showed a higher expression of ASIC4 than the EG cohort (p < 0.05). The results gathered in this study revealed the capacity of water temperature to influence both gonadal differentiation and growth in this gonochoristic fish species, and suggests the possible role of ASIC2 and ASIC4 in gonad differentiation and gamete development in D. labrax.

Local effect of allopregnanolone in rat ovarian steroidogenesis, follicular and corpora lutea development

Allopregnanolone (ALLO) is a known neurosteroid and a progesterone metabolite synthesized in the ovary, CNS, PNS, adrenals and placenta. Its role in the neuroendocrine control of ovarian physiology has been studied, but its in situ ovarian effects are still largely unknown. The aims of this work were to characterize the effects of intrabursal ALLO administration on different ovarian parameters, and the probable mechanism of action. ALLO administration increased serum progesterone concentration and ovarian 3β-HSD2 while decreasing 20α-HSD mRNA expression. ALLO increased the number of atretic follicles and the number of positive TUNEL granulosa and theca cells, while decreasing positive PCNA immunostaining. On the other hand, there was an increase in corpora lutea diameter and PCNA immunostaining, whereas the count of TUNEL-positive luteal cells decreased. Ovarian angiogenesis and the immunohistochemical expression of GABAA receptor increased after ALLO treatment. To evaluate if the ovarian GABAA receptor was involved in these effects, we conducted a functional experiment with a specific antagonist, bicuculline. The administration of bicuculline restored the number of atretic follicles and the diameter of corpora lutea to normal values. These results show the actions of ALLO on the ovarian physiology of the female rat during the follicular phase, some of them through the GABAA receptor. Intrabursal ALLO administration alters several processes of the ovarian morpho-physiology of the female rat, related to fertility and oocyte quality.

Characterization of the human fetal gonad and reproductive tract by single-cell transcriptomics

During human fetal development, sex differentiation occurs not only in the gonads but also in the adjacent developing reproductive tract. However, while the cellular composition of male and female human fetal gonads is well described, that of the adjacent developing reproductive tract remains poorly characterized. Here, we performed single-cell transcriptomics on male and female human fetal gonads together with the adjacent developing reproductive tract from first and second trimesters, highlighting the morphological and molecular changes during sex differentiation. We validated different cell populations of the developing reproductive tract and gonads and compared the molecular signatures between the first and second trimesters, as well as between sexes, to identify conserved and sex-specific features. Together, our study provides insights into human fetal sex-specific gonadogenesis and development of the reproductive tract beyond the gonads.

Transposable elements acquire time- and sex-specific transcriptional and epigenetic signatures along mouse fetal gonad development

Gonadal sex determination in mice is a complex and dynamic process, which is crucial for the development of functional reproductive organs. The expression of genes involved in this process is regulated by a variety of genetic and epigenetic mechanisms. Recently, there has been increasing evidence that transposable elements (TEs), which are a class of mobile genetic elements, play a significant role in regulating gene expression during embryogenesis and organ development. In this study, we aimed to investigate the involvement of TEs in the regulation of gene expression during mouse embryonic gonadal development. Through bioinformatics analysis, we aimed to identify and characterize specific TEs that operate as regulatory elements for sex-specific genes, as well as their potential mechanisms of regulation. We identified TE loci expressed in a time- and sex-specific manner along fetal gonad development that correlate positively and negatively with nearby gene expression, suggesting that their expression is integrated to the gonadal regulatory network. Moreover, chromatin accessibility and histone post-transcriptional modification analyses in differentiating supporting cells revealed that TEs are acquiring a sex-specific signature for promoter-, enhancer-, and silencer-like elements, with some of them being proximal to critical sex-determining genes. Altogether, our study introduces TEs as the new potential players in the gene regulatory network that controls gonadal development in mammals.

Semen microbiota are dramatically altered in men with abnormal sperm parameters

There has recently been an explosion of studies implicating the human microbiome in playing a critical role in many disease and wellness states. The etiology of abnormal semen analysis (SA) parameters is not identified in 30% of cases; investigations involving the semen microbiome may bridge this gap. Here, we explore the relationship between the semen microbiome and alterations of sperm parameters. We recruited men presenting for fertility evaluation or vasectomy consultation with proven biological paternity. SA and next generation sequencing was performed. Differential abundance testing using Analysis of composition of Microbiota with Bias Correction (ANCOM-BC) was performed along with canonical correlational analysis for microbial community profiling. Men with abnormal (N = 27) sperm motility showed a higher abundance of Lactobacillus iners compared to those with normal (N = 46) sperm motility (mean proportion 9.4% versus 2.6%, p = 0.046). This relationship persisted on canonical correlational analysis (r = 0.392, p = 0.011). Men with abnormal sperm concentration (N = 20) showed a higher abundance of Pseudomonas stutzeri (2.1% versus 1.0%, p = 0.024) and Pseudomonas fluorescens (0.9% versus 0.7%, p = 0.010), but a lower abundance of Pseudomonas putida (0.5% versus 0.8%, p = 0.020), compared to those with normal sperm concentration (N = 53). Major limitations are related to study design (cross-sectional, observational). Our results suggest that a small group of microorganisms may play a critical role in observed perturbations of SA parameters. Some of these microbes, most notably Lactobacillus iners, have been described extensively within other, fertility-related, contexts, whereas for others, this is the first report where they have potentially been implicated. Advances in our understanding of the semen microbiome may contribute to potentially new therapeutic avenues for correcting impairments in sperm parameters and improving male fertility.

hsd17b1 is a key gene for ovarian differentiation of the Siberian sturgeon

This is the first work using gonads from undifferentiated, genetically-sexed Siberian sturgeon describing expression changes in genes related to steroid synthesis and female and male sex differentiation. One factor identified as relevant for ovarian differentiation was the gene coding for the enzyme Hsd17b1, which converts estrone into estradiol-17β. hsd17b1 was highly activated in female gonads at 2.5 months of age, around the onset of sex differentiation, preceding activation of two other genes involved in estrogen production (cyp19a1 and foxl2). hsd17b1 was also strongly repressed in males. Two known foxl2 paralogs are found in Siberian sturgeon-foxl2 and foxl2l-but only foxl2 appeared to be associated with ovarian differentiation. With regard to the male pathway, neither 11-oxygenated androgens nor classic male genes (amh, dmrt1, sox9, and dhh) were found to be involved in male sex differentiation, leaving open the question of which genes participate in early male gonad development in this ancient fish. Taken together, these results indicate an estrogen-dependence of female sex differentiation and 11-oxygenated androgen-independence of male sex differentiation.

Sleep apnea syndrome associated with gonadal hormone imbalance (Review)

Patients with obstructive sleep apnea exhibit an increased risk of developing gonadal disorders. Because a notable number of people worldwide have sleep respiratory and reproductive disorders, it is essential to recognize the association between local upper airway dysfunction and its gonadal effects. Repeated breathing pauses cause sleep fragmentation, disorganization of sleep cycles and stages, sympathetic activation, intermittent hypoxemia and systemic inflammation. Nocturnal intermittent hypoxemia has a direct central effect on neurotransmitters, with disturbances in the normal production of hypothalamic-pituitary hormones. Awakenings and micro-awakenings at the end of apneic episodes produce a central stress responsible for hormonal changes and subsequent endocrine imbalances. The aim of the present study was to investigate the impact of obstructive sleep apnea syndrome (OSAS) on gonadal hormonal homeostasis and its consequences. Recognizing and understanding how local upper airway dysfunction causes gonadal imbalance may facilitate better care for patients with OSAS. Although there may be a direct relationship between sleep-disordered breathing and gonadal function mediated by hormones via the hypothalamic-pituitary-gonadal axis, to date, current therapies have not been effective.

A Metabolomic Analysis to Assess the Responses of the Male Gonads of Mytilus galloprovincialis after Heavy Metal Exposure

In recent years, metabolomics has become a valuable new resource in environmental monitoring programs based on the use of bio-indicators such as Mytilus galloprovincialis. The reproductive system is extremely susceptible to the effects of environmental pollutants, and in a previous paper, we showed metabolomic alterations in mussel spermatozoa exposed to metal chlorides of copper, nickel, and cadmium, and the mixture with these metals. In order to obtain a better overview, in the present work, we evaluated the metabolic changes in the male gonad under the same experimental conditions used in the previous work, using a metabolomic approach based on GC-MS analysis. A total of 248 endogenous metabolites were identified in the male gonads of mussels. Statistical analyses of the data, including partial least squares discriminant analysis, enabled the identification of key metabolites through the use of variable importance in projection scores. Furthermore, a metabolite enrichment analysis revealed complex and significant interactions within different metabolic pathways and between different metabolites. Particularly significant were the results on pyruvate metabolism, glycolysis, and gluconeogenesis, and glyoxylate and dicarboxylate metabolism, which highlighted the complex and interconnected nature of these biochemical processes in mussel gonads. Overall, these results add new information to the understanding of how certain pollutants may affect specific physiological functions of mussel gonads.

Intra-uterine programming of future fertility

The developmental origins of health and disease (DOHaD) shows that a relationship exists between parental environment at large, foeto-placental development and the risk for the offspring to develop non-transmittable disease(s) in adulthood. This concept has been validated in both humans and livestock. In mammals, after fertilization and time spent free in the maternal reproductive tract, the embryo develops a placenta that, in close relationship with maternal endometrium, is the organ responsible for exchanges between dam and foetus. Any modification of the maternal environment can lead to adaptive mechanisms affecting placental morphology, blood flow, foetal-maternal exchanges (transporters) and/or endocrine function, ultimately modifying placental efficiency. Among deleterious environments, undernutrition, protein restriction, overnutrition, micronutrient deficiencies and food contaminants can be outlined. When placental adaptive capacities become insufficient, foetal growth and organ formation is no longer optimal, including foetal gonadal formation and maturation, which can affect subsequent offspring fertility. Since epigenetic mechanisms have been shown to be key to foetal programming, epigenetic modifications of the gametes may also occur, leading to inter-generational effects. After briefly describing normal gonadal development in domestic species and inter-species differences, this review highlights the current knowledge on intra-uterine programming of offspring fertility with a focus on domestic animals and underlines the importance to assess transgenerational effects on offspring fertility at a time when new breeding systems are developed to face the current climate changes.

DMRT1 is a testis-determining gene in rabbits and is also essential for female fertility

DMRT1 is the testis-determining factor in several species of vertebrates, but its involvement in mammalian testes differentiation, where SRY is the testis-determining gene, remains ambiguous. So far, DMRT1 loss-of-function has been described in two mammalian species and induces different phenotypes: Disorders of Sex Development (46, XY DSD) in men and male infertility in mice. We thus abolished DMRT1 expression by CRISPR/Cas9 in a third species of mammal, the rabbit. First, we observed that gonads from XY DMRT1-/- rabbit fetuses differentiated like ovaries, highlighting that DMRT1 is involved in testis determination. In addition to SRY, DMRT1 is required in the supporting cells to increase the expression of the SOX9 gene, which heads the testicular genetic cascade. Second, we highlighted another function of DMRT1 in the germline since XX and XY DMRT1-/- ovaries did not undergo meiosis and folliculogenesis. XX DMRT1-/- adult females were sterile, showing that DMRT1 is also crucial for female fertility. To conclude, these phenotypes indicate an evolutionary continuum between non-mammalian vertebrates such as birds and non-rodent mammals. Furthermore, our data support the potential involvement of DMRT1 mutations in different human pathologies, such as 46, XY DSD as well as male and female infertility.

Distribution of Essential and Toxic Elements in Pelecus cultratus Tissues and Risk Assessment for Consumer Health

Nowadays, the problem of inland water pollution is acute. It is caused by vast industrial growth and agricultural intensification. Concentrations of Cd, Pb, Zn, Cu, Mn, Fe, Mg, and Kwere determined in the muscles, liver, and gonads sabrefish from Rybinsk Reservoir areas with different anthropogenic loads. The tissue samples were analyzed by atomic absorption spectrometry. Heavy metals accumulated more intensively in the body of fish from more polluted areas of the reservoir. Among the analyzed elements, the maximum accumulation levels were found for K, Zn, and Fe and the minimum levels were observed for Cd and Pb. The gonads contained the largest concentration of Cd and Mn, the muscles contained the highest concentrations of Mg, and the other elements mainly accumulated in the liver of sabrefish. The THQ and HI values for all elements did not exceed 1, which suggests that there is no potential non-carcinogenic risk to human health. The target values of carcinogenic risk (TR) for cadmium ranged from 8.32 × 10-6 to 1.22 × 10-4 in the muscles. The increased content of cadmium in the gonads of sabrefish not only poses a risk to human health, but also to the reproduction of this species in the Rybinsk Reservoir.

Lycopene supplementation: effects on oxidative stress, sex hormones, gonads and thyroid tissue in tilapia Oreochromis niloticus during Harness® exposure

Harness® is a commercial herbicide that contains acetochlor at a concentration of 84% as an active ingredient. Ubiquitous, persistent, and substantial uses of Harness® in agricultural processes have resulted in the pollution of nearby water sources, posing a threat to various aquatic biotas, including fish. The effects of Harness® toxicity on fish health are little known. So, this study aimed to describe the impact of herbicide Harness® on the oxidative stress and reproductive and thyroid performance of male and female tilapia (Oreochromis niloticus) and also investigate the prospective role of the natural antioxidant lycopene supplementation in dismissing the adverse properties of Harness®. Antioxidant enzyme (catalase, superoxide dismutase, and total antioxidant capacity) and hormone measurements (T, E2, T3, and T4) were carried out, and gonadal and thyroid follicle histological sections were examined as a method to investigate the effects of Harness® toxicity on fish. Male and female tilapia were exposed to 10 μmol/L and 100 μmol/L of Harness® and treated with 10 mg lycopene/kg for 15 days of exposure. Our results demonstrated that the antioxidant enzyme activity was altered by Harness exposure and serum T for both males and females dropped; also, female E2 levels decreased, but male E2 increased. Exposure to higher dose of Harness® induced elevation in both T3 and T4 levels, although the low exposure dose stimulated T4 levels. Harness® exposure prompted histological variations and degenerative changes in testicular, ovarian, and thyroid follicle tissues. Lycopene supplement administration diminished oxidative stress induced by Harness®, alleviating its endocrine disparaging effects by neutralizing T3, T4, T, and E2 and ameliorating the histological structure of gonadal and thyroid tissues. In conclusion, lycopene supplementation was preformed to normalize the alterations and oxidative damage caused by Harness® in Nile tilapia, suggesting that lycopene-supplemented diet functioned as potent antioxidants and had the ability to alleviate oxidative stress and thyroid and reproductive toxicity caused by herbicide Harness®. Moreover, it is crucial to take appropriate care when consuming herbicides to defend the aquatic environment.

AXL/Gas6 signaling mechanisms in the hypothalamic-pituitary-gonadal axis

AXL is a receptor tyrosine kinase commonly associated with a variety of human cancers. Along with its ligand Gas6 (growth arrest-specific protein 6), AXL is emerging as an important regulator of neuroendocrine development and function. AXL signaling in response to Gas6 binding impacts neuroendocrine structure and function at the level of the brain, pituitary, and gonads. During development, AXL has been identified as an upstream inhibitor of gonadotropin receptor hormone (GnRH) production and also plays a key role in the migration of GnRH neurons from the olfactory placode to the forebrain. AXL is implicated in reproductive diseases including some forms of idiopathic hypogonadotropic hypogonadism and evidence suggests that AXL is required for normal spermatogenesis. Here, we highlight research describing AXL/Gas6 signaling mechanisms with a focus on the molecular pathways related to neuroendocrine function in health and disease. In doing so, we aim to present a concise account of known AXL/Gas6 signaling mechanisms to identify current knowledge gaps and inspire future research.

Human Tissues Exhibit Diverse Composition of Translation Machinery

While protein synthesis is vital for the majority of cell types of the human body, diversely differentiated cells require specific translation regulation. This suggests the specialization of translation machinery across tissues and organs. Using transcriptomic data from GTEx, FANTOM, and Gene Atlas, we systematically explored the abundance of transcripts encoding translation factors and aminoacyl-tRNA synthetases (ARSases) in human tissues. We revised a few known and identified several novel translation-related genes exhibiting strict tissue-specific expression. The proteins they encode include eEF1A1, eEF1A2, PABPC1L, PABPC3, eIF1B, eIF4E1B, eIF4ENIF1, and eIF5AL1. Furthermore, our analysis revealed a pervasive tissue-specific relative abundance of translation machinery components (e.g., PABP and eRF3 paralogs, eIF2B and eIF3 subunits, eIF5MPs, and some ARSases), suggesting presumptive variance in the composition of translation initiation, elongation, and termination complexes. These conclusions were largely confirmed by the analysis of proteomic data. Finally, we paid attention to sexual dimorphism in the repertoire of translation factors encoded in sex chromosomes (eIF1A, eIF2γ, and DDX3), and identified the testis and brain as organs with the most diverged expression of translation-associated genes.

Characterization of serum and tissue oxytocinase and tissue oxytocin in the pregnant and non-pregnant mare

Oxytocin is a hormone with functions in: reproduction, maternal bonding, milk ejection, and feeding/social behavior, and is reported to be present in a variety of tissues. Our goal is to characterize oxytocin and leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase), a key regulator of oxytocin in mares. We measured serum and tissue LNPEP by ELISA from ovulation (D0) until D21-22 in non-pregnant (n = 5) and pregnant mares (n = 6); and in periparturient and postpartum mares (n = 18). Placenta (n = 7) and homogenized tissue of diestrus mares (n = 6) were evaluated using protein determinations and LNPEP ELISAs. Identification of LNPEP and OXT protein in tissues was also performed via western blot, immunohistochemistry and liquid chromatography-mass spectrometry (LC-MS/MS). Furthermore, in situ hybridization was performed for LNPEP and OXT on endometrium, myometrium, pituitary and corpus luteum (CL). Serum LNPEP concentration were similar. Placental LNPEP U/mg protein was highest in the body and pregnant horn. The highest to lowest LNPEP U/mg protein by tissue were: myometrium > follicle wall > endometrium > kidney > CL > liver. Oxytocin was identified in the equine pituitary, CL and placenta and is likely to act in autocrine or paracrine manner, while LNPEP may act systemically and locally to regulate the availability of OXT.

Insights into Early Ontogenesis of Salmo salar: RNA Extraction, Housekeeping Gene Validation and Transcriptional Expression of Important Primordial Germ Cell and Sex-Determination Genes

The challenge in extracting high-quality RNA impedes the investigation of the transcriptome of developing salmonid embryos. Furthermore, the mRNA expression pattern of important PGC and SD genes during the initial embryonic development of Salmo salar is yet to be studied. So, in the present study, we aimed to isolate high-quality RNA from eggs and developing embryos to check vasa, dnd1, nanos3a, sdf1, gsdf, amh, cyp19a, dmrt1 and foxl2 expression by qPCR. Additionally, four HKGs (GAPDH, UB2L3, eEf1a and β-actin) were validated to select the best internal control for qPCR. High-quality RNA was extracted, which was confirmed by spectrophotometer, agarose gel electrophoresis and Agilent TapeStation analysis. UB2L3 was chosen as a reference gene because it exhibited lower intra- and inter-sample variation. vasa transcripts were expressed in all the developmental stages, while dnd1 was expressed only up to 40 d°C. Nanos3a was expressed in later stages and remained at its peak for a shorter period, while sdf1 showed an irregular pattern of mRNA expression. The mRNA expression levels of SD genes were observed to be upregulated during the later stages of development, prior to hatching. This study presents a straightforward methodology for isolating high-quality RNA from salmon eggs, and the resulting transcript profiles of significant PGC and SD genes in S. salar could aid in improving our comprehension of reproductive development in this commercially important species.

Ultrasonographic sex determination of the flathead grey mullet (Mugil cephalus)

BACKGROUND

Determination of sex in fish without external sexual dimorphism is important. Sex determination of the flathead grey mullet (Mugil cephalus) in the culture system and spawn-producing and fish reproduction system is very important. Currently, there are several methods to determine the sex of fish; however, they are time-consuming, expensive and sometimes dangerous for the fish.

OBJECTIVE

The purpose of this study was the sex determination of flathead grey mullet by ultrasonography as a safe and accurate method.

METHODS

In this regard, 30 flathead grey mullets (early in their maturation) from a farm in Gomishan-Golestan province, Iran were examined using a portable ultrasound machine with a 6-12 MHz waterproof linear transducer. Scanning was performed on the ventral body surface in the sagittal and transverse planes, between ventral and anal fins.

RESULTS

Differences in shape, qualitative size, echogenicity and the wall layers of the ovary and testis were evaluated for sex determination. Results of ultrasonography were confirmed immediately at necropsy. Ultrasonographic accuracy for sex determination was 100%. The speed of the procedure was around 30 s per fish.

CONCLUSIONS

Overall, the sex determination of flathead grey mullet by ultrasonography was high in accuracy and speed, non-invasive and safe for fish and consumers, and may be considered a priority. Place of the organs in the M. cephalus coelomic cavity and the obtained experience showed that for rapid and easy sex identification, the best place to put the transducer is on the ventral surface of the fish in the caudal part of the coelomic cavity for taking transverse and sagittal ultrasonograms.

Complete androgen insensitivity syndrome: a case report and literature review

Complete androgen insensitivity syndrome (CAIS) is a rare disease that can be easily misdiagnosed. Before puberty, this condition is easily misdiagnosed as an inguinal hernia. This case report describes a 31-year-old phenotypically female patient with CAIS who was misdiagnosed twice previously with an inguinal hernia. Her karyotype analysis showed that she was 46, XY. She underwent a bilateral gonadectomy and long-term hormone replacement therapy. A Leydig cell tumour of the right testis was diagnosed postoperatively. This report also reviews the current understanding of the diagnosis and treatment of CAIS.

Polyorchidism: An Up-to-Date Systematic Review

Polyorchidism is a rare male urogenital tract anomaly characterized by at least one supernumerary testis in the scrotum or ectopically. According to data based on our systematic review, 76% of the supernumerary testes (SNTs) were located in the scrotum, and 24% were extra-scrotal (p < 0.001). Among testes located outside the scrotum, 87% were found in the inguinal canal and 13% in the abdominal cavity. In 80% of cases, the diagnosis of SNT was made based on imaging tests, and the remaining 20% of cases were detected incidentally during surgery. The imaging tests performed (US or MRI) resulted in a significantly higher rate of patients who qualified for observation vs. surgical treatment (45% vs. 35%, p < 0.001). The most common conditions associated with SNT were ipsilateral inguinal hernia (15% of cases) and cryptorchidism (15% of cases). Surgery (orchidopexy/orchidectomy) was performed on 54% of patients with SNT, and the decision to observe the SNT was made in a total of 46% of patients (p = 0.001). The therapeutic approach depends on the location of the SNT and the presence of factors that raise suspicion of neoplastic proliferation.

Assessing spermatozoal small ribonucleic acids and their relationship to blastocyst development in idiopathic infertile males

Clinical testing strategies for diagnosing male factor infertility are limited. A deeper analysis of spermatozoa-derived factors could potentially diagnose some cases of 'unexplained infertility'. Spermatozoa carry a rich and dynamic profile of small RNAs, which have demonstrated potential developmental importance and association with fertility status. We used next-generation sequencing to correlate sperm small RNA profiles of normozoospermic males (n = 54) with differing blastocyst development rates, when using young donor oocytes. While ribosomal RNAs accounted for the highest number of sequencing reads, transfer RNA fragments of tRNA^Gly/GCC and tRNA^Val-CAC were the most abundant sequences across all sperm samples. A total of 324 small RNAs were differentially expressed between samples with high (n = 18) and low (n = 14) blastocyst rates (p-adj < 0.05). Ninety three miRNAs were differentially expressed between these groups (p-adj < 0.05). Differentially expressed transfer RNA fragments included: 5'-tRF-Asp-GTC; 5'-tRF-Phe-GAA; and 3'-tRF-Ser-GCA. Differentially expressed miRNAs included: let-7f-2-5p; miR-4755-3p; and miR-92a-3p. This study provides the foundation on which to validate a clinical panel of fertility-related sperm small RNAs, as well as to pursue potential mechanisms through which they alter blastocyst development.

Exposure to Low Zearalenone Doses and Changes in the Homeostasis and Concentrations of Endogenous Hormones in Selected Steroid-Sensitive Tissues in Pre-Pubertal Gilts

This study was undertaken to analyze whether prolonged exposure to low-dose zearalenone (ZEN) mycotoxicosis affects the concentrations of ZEN, α-zearalenol (α-ZEL), and β-zearalenol (β-ZEL) in selected reproductive system tissues (ovaries, uterine horn-ovarian and uterine sections, and the middle part of the cervix), the hypothalamus, and pituitary gland, or the concentrations of selected steroid hormones in pre-pubertal gilts. For 42 days, gilts were administered per os different ZEN doses (MABEL dose [5 µg/kg BW], the highest NOAEL dose [10 µg/kg BW], and the lowest LOAEL dose [15 µg/kg BW]). Tissue samples were collected on days seven, twenty-one, and forty-two of exposure to ZEN (exposure days D1, D2, and D3, respectively). Blood for the analyses of estradiol and progesterone concentrations was collected in vivo on six dates at seven-day intervals (on analytical dates D1-D6). The analyses revealed that both ZEN and its metabolites were accumulated in the examined tissues. On successive analytical dates, the rate of mycotoxin accumulation in the studied tissues decreased gradually by 50% and proportionally to the administered ZEN dose. A hierarchical visualization revealed that values of the carry-over factor (CF) were highest on exposure day D2. In most groups and on most exposure days, the highest CF values were found in the middle part of the cervix, followed by the ovaries, both sections of the uterine horn, and the hypothalamus. These results suggest that ZEN, α-ZEL, and β-ZEL were deposited in all analyzed tissues despite exposure to very low ZEN doses. The presence of these undesirable compounds in the examined tissues can inhibit the somatic development of the reproductive system and compromise neuroendocrine coordination of reproductive competence in pre-pubertal gilts.

Sound production and mechanism in the cryptic cusk-eel Parophidion vassali

This study investigates the sounds and the anatomy of the sound-producing organ in the male and female sand-dwelling cusk-eel Parophidion vassali. Although both sexes have similar external phenotype, they can be distinguished by their sonic apparatus and sounds. As in many Ophioidei, Parophidion vassali presents a panel of highly derived characters. Fish possess three pairs of sonic muscles, and males have mineralized swimbladder caps on which inserts the ventral sonic muscle, a neural arch that pivots, a stretchable swimbladder fenestra, an osseous swimbladder plate and a rounded pressure-release membrane in the caudal swimbladder. Females, however, do not possess anterior swimbladder caps, a swimbladder fenestra and the caudal rounded membrane. Males possess the unusual ability to produce sounds starting with a set of low amplitude pulses followed by a second set with higher amplitudes clearly dividing each sound unit into two parts. Females do not vary their sound amplitude in this way: they produce shorter sounds and pulse periods but with a higher peak frequency. Morphology and sound features support the sound-producing mechanism is based on a rebound system (i.e. quick backward snap of the anterior swimbladder). Based on features of the sounds from tank recordings, we have putatively identified the sound of male Parophidion vassali at sea. As these species are ecologically cryptic, we hope this work will allow assessment and clarify the distribution of their populations.

Sex-Biased miRNAs in the Gonads of Adult Chinese Alligator (Alligator sinensis) and Their Potential Roles in Sex Maintenance

MicroRNA (miRNA) is a category of single-stranded non-coding small RNA (sRNA) that regulates gene expression by targeting mRNA. It plays a key role in the temperature-dependent sex determination of Chinese alligator (Alligator sinensis), a reptile whose sex is determined solely by the temperature during the incubation period and remains stable thereafter. However, the potential function of miRNAs in the gonads of adult Chinese alligators is still unclear. Here, we prepared and sequenced sRNA libraries of adult female and male alligator gonads, from breeding (in summer) and hibernating (in winter) animals. We obtained 130 conserved miRNAs and 683 novel miRNAs, which were assessed for sex bias in summer and winter; a total of 65 miRNAs that maintained sex bias in both seasons were identified. A regulatory network of sex-biased miRNAs and genes was constructed. Sex-biased miRNAs targeted multiple genes in the meiosis pathway of adult Chinese alligator oocytes and the antagonistic gonadal function maintenance pathway, such as MOS, MYT1, DMRT1, and GDF9. Our study emphasizes the function of miRNA in the epigenetic mechanisms of sex maintenance in crocodilians.

Ovary micromorphology and oogenesis in a rhyacodriline oligochaete (Clitellata: Naididae, Rhyacodrilinae)

The main goal of the paper is to describe the ovary organization and oogenesis in Peristodrilus montanus, an aquatic oligochaete of the subfamily Rhyacodrilinae. The presented analysis will not only enrich the knowledge about how eggs are formed but, because of the suggested conservatism of ovary organization in clitellate annelids, can contribute to disentangling the complex phylogenetic relationships of the rhyacodrilines within Naididae. The paired, conically shaped ovaries are located in segment XI. They are composed of a dozen or so syncytial germ-line cysts, which are associated with somatic cells. Each germ cell in a cyst has one intercellular bridge that joins it to a central and anuclear cytoplasmic mass, the cytophore. This pattern of cyst organization is typical for all clitellates that have been studied to date. Initially, the germ cells in a cyst undergo a synchronous development, however, there is no synchrony between cysts, and therefore there is a developmental gradient (oogonia, pre-diplotene germ cells, germ cells in diplotene) of oogenesis along the long ovary axis. The cysts are composed of a maximum of 32 cells. Cysts with cells in diplotene detach from the ovaries and the extraovarian phase of oogenesis begins. The developmental synchrony is lost, one cell (an oocyte) per cyst starts to gather cell components and yolk and grows considerably. The remaining cells grow to some extent and function as nurse cells. Like in other microdriles, P. montanus oocytes are rich in yolk; other features of oogenesis are also similar to those that are known from other microdrile taxa. The system of ovary organization found in the studied species is broadly similar to the corresponding features known from Naidinae and Phreodrilidae and, to some extent, in Enchytraeidae. However, this system is different from the one that is known in Tubificinae, Limnodriloidinae and Branchiurinae. This article is protected by copyright. All rights reserved.

Society for Endocrinology UK Guidance on the initial evaluation of a suspected difference or disorder of sex development (Revised 2021)

It is paramount that any child or adolescent with a suspected difference or disorder of sex development (DSD) is assessed by an experienced clinician with adequate knowledge about the range of conditions associated with DSD and is discussed with the regional DSD service. In most cases, the paediatric endocrinologist within this service acts as the first point of contact but involvement of the regional multidisciplinary service will also ensure prompt access to specialist psychology and nursing care. The underlying pathophysiology of DSD and the process of delineating this should be discussed with the parents and affected young person with all diagnostic tests undertaken in a timely fashion. Finally, for rare conditions such as these, it is imperative that clinical experience is shared through national and international clinical and research collaborations.

Clustering of Sex-Biased Genes and Transposable Elements in the Genome of the Medaka Fish Oryzias latipes

Although genes with similar expression patterns are sometimes found in the same genomic regions, almost nothing is known about the relative organization in genomes of genes and transposable elements (TEs), which might influence each other at the regulatory level. In this study, we used transcriptomic data from male and female gonads of the Japanese medaka Oryzias latipes to define sexually biased genes and TEs and analyze their relative genomic localization. We identified 20,588 genes expressed in the adult gonads of O. latipes. Around 39% of these genes are differentially expressed between male and female gonads. We further analyzed the expression of TEs using the program SQuIRE and showed that more TE copies are overexpressed in testis than in ovaries (36% vs. 10%, respectively). We then developed a method to detect genomic regions enriched in testis- or ovary-biased genes. This revealed that sex-biased genes and TEs are not randomly distributed in the genome and a part of them form clusters with the same expression bias. We also found a correlation of expression between TE copies and their closest genes, which increases with decreasing intervening distance. Such a genomic organization suggests either that TEs hijack the regulatory sequences of neighboring sexual genes, allowing their expression in germ line cells and consequently new insertions to be transmitted to the next generation, or that TEs are involved in the regulation of sexual genes, and might therefore through their mobility participate in the rewiring of sex regulatory networks.

Estimation of radiation gonadal doses for the American-Ukrainian trio study of parental irradiation in Chornobyl cleanup workers and evacuees and germline mutations in their offspring

Radiation doses of parents exposed from the Chornobyl accident as cleanup workers or evacuees were estimated in the National Cancer Institute-National Research Center for Radiation Medicine trio (i.e. father, mother, offspring) study aimed at investigating the radiation effects on germlinede novomutations in children as well as other outcomes. Paternal (testes) and maternal (ovaries) gonadal doses were calculated along with associated uncertainty distributions for the following exposure pathways: (a) external irradiation during the cleanup mission, (b) external irradiation during residence in Pripyat, and (c) external irradiation and (d) ingestion of radiocesium isotopes, such as¹³⁴Cs and¹³⁷Cs, during residence in settlements other than Pripyat. Gonadal doses were reconstructed for 298 trios for the periods from the time of the accident on 26 April 1986 to two time points before the child's date of birth (DOB): 51 (DOB-51) and 38 (DOB-38) weeks. The two doses, DOB-51 and DOB-38 were equal (within 1 mGy) in most instances, except for 35 fathers where the conception of the child occurred within 3 months of exposure or during exposure. The arithmetic mean of gonadal DOB-38 doses was 227 mGy (median: 11 mGy, range 0-4080 mGy) and 8.5 mGy (median: 1.0 mGy, range 0-550 mGy) for fathers and mothers, respectively. Gonadal doses varied considerably depending on the exposure pathway, the highest gonadal DOB-38 doses being received during the cleanup mission (mean doses of 376 and 34 mGy, median of 144 and 7.4 mGy for fathers and mothers, respectively), followed by exposure during residence in Pripyat (7.7 and 13 mGy for mean, 7.2 and 6.2 mGy for median doses) and during residence in other settlements (2.0 and 2.1 mGy for mean, 0.91 and 0.81 mGy for median doses). Monte Carlo simulations were used to estimate the parental gonadal doses and associated uncertainties. The geometric standard deviations (GSDs) in the individual parental stochastic doses due to external irradiation during the cleanup mission varied from 1.2 to 4.7 (mean of 1.8), while during residence in Pripyat they varied from 1.4 to 2.8 (mean of 1.8), while the mean GSD in doses received during residence in settlements other than Pripyat was 1.3 and 1.4 for external irradiation and ingestion of radiocesium isotopes, respectively.

Seasonal reproduction and gonadal function: A focus on humans starting from animal studies

Photoperiod impacts reproduction in many species of mammals. Mating occurs at specific seasons to achieve reproductive advantages, such as optimization of offspring survival. Light is the main regulator of these changes during the photoperiod. Seasonally breeding mammals detect and transduce light signals through extraocular photoreceptor, regulating downstream melatonin-dependent peripheral circadian events. In rodents, hormonal reduction and gonadal atrophy occur quickly, and consensually with short-day periods. It remains unclear whether photoperiod influences human reproduction. Seasonal fluctuations of sex hormones have been described in humans, although they seem to not imply adaptative seasonal pattern in human gonads. This review discusses current knowledge about seasonal changes in the gonadal function of vertebrates, including humans. The photoperiod-dependent regulation of hypothalamic-pituitary-gonadal axis, as well as morphological and functional changes of the gonads are evaluated herein. Endocrine and morphological variations of reproductive functions, in response to photoperiod, are of interest as they may reflect the nature of past population selection for adaptative mechanisms that occurred during evolution.

Geographic variability in the gonadal development and sexual ontogeny of Hemigymnus, Cheilinus and Oxycheilinus wrasses among Indo-Pacific coral reefs

Patterns of reproductive ontogeny in four species of coral reef wrasses (F: Labridae) Hemigymnus melapterus, Hemigymnus fasciatus, Cheilinus fasciatus and Oxycheilinus digramma were investigated. Populations of each species were sampled from two island groups of the central Great Barrier Reef (GBR), Australia, and from coral reefs in the central Philippines. These three sampling locations span 30° of latitude. The GBR and Philippine reefs experience biologically significant differences in water temperature, geography and human activity. The studied wrasses are effectively unfished in Australia but heavily fished in the Philippines. Gonad weights, histology and demographic data were obtained across the entire size and age range of H. melapterus, C. fasciatus and O. digramma from all locations. Analysis identified three processes of male recruitment: functional gonochorism and both forms of protogynous hermaphroditism, monandry and diandry. The expression of these distinct sexual ontogenies was locality dependent. Populations of H. melapterus, H. fasciatus, C. fasciatus and O. digramma on the GBR showed consistently uniform patterns of sexual ontogeny, with all species being exclusively monandric. H. melapterus, C. fasciatus and O. digramma in the Philippines displayed complex sexual ontogenies, with all species showing histological evidence of both diandry and functional gonochorism. Reproductive investment in gonadal tissue, and population sex structure, also differed between GBR and Philippine coral reefs. Philippine populations had substantially lower gonado-somatic indices than populations on the GBR. Nonetheless, Philippine populations matured more rapidly and displayed a protracted timing of sex change over a large size and age range. Thus, mature females appeared earlier and persisted later into ontogeny in the Philippines than on GBR reefs. Protracted timing of sex change on Philippine reefs is likely linked to the presence of primary males in the population, which is known to reduce the strength of selection for mature females to undergo sex change and become male. Hypotheses based on social structure of fish populations, environmental factors and evolutionary history were developed to account for the different patterns of sexual ontogeny in the focal wrasses.

Effect of celecoxib against different developmental stages of experimental Schistosoma mansoni infection

Due to the high prevalence of schistosomiasis and the wide use of praziquantel solely for mass drug administration to control the disease, there is a great concern about the potential emergence of reduced susceptibility strains. This, together with the concern that praziquantel is ineffective against juvenile worms highlight the importance of developing an alternative anti-schistosomal drug. Using nonsteroidal anti-inflammatory drugs against schistosome infection is considerable. The present study evaluated the effect of oral administration of five days celecoxib regimen (20 mg/kg/day) against different developmental stages of Schistosoma mansoni infection. This regimen induced significant reduction in worm burden, tissue egg count, individual female fecundity and the mean percentage of immature and mature eggs with increased mean percentage of dead eggs. More importantly, celecoxib was more potent than praziquantel in all these parasitological parameters (except in the worm burden when given against the adult stage where the difference was statistically non-significant). Scanning and transmission electron microscopy of the adult worms revealed severe tegumental damage, laceration of the muscular layers and oedema of the syncytial layer. There was disruption of the testicular, ovarian and vitelline glandular tissues with signs of apoptosis and abnormalities of the spermatozoa and the oocytes. Additionally, celecoxib induced reduction in the number and the size of the hepatic granulomata and also amelioration of the hepatic tissue pathology.

Sodium Fluoride In Vitro Treatment Affects the Expression of Gonadotropin and Steroid Hormone Receptors in Chicken Embryonic Gonads

Simple Summary

Effects of in vitro sodium fluoride (NaF) treatment on the mRNA expression of luteinizing hormone receptor (LHR), follicle-stimulating hormone receptor (FSHR), estrogen receptors (ESR1 and ESR2), progesterone receptor (PGR), and the immunolocalization of PGRs were examined in gonads of 14-day-old chicken embryos. In the ovary, the NaF treatment significantly increased mRNA levels of all investigated receptors. In the testes, the lowest applied dose of NaF (1.7 mM) significantly decreased the expression of FSHR, ESR1, ESR2, and PGR. Alternatively, the higher NaF dose (7.1 mM) elevated PGR mRNA level in the male gonad. Immunohistochemical analysis revealed that the NaF exposure increased PGR expression in the ovarian cortex, while it decreased its expression in the testes. Collectively, these data indicate that: (i) NaF may disturb the chicken embryonic development, and (ii) different mechanisms of this toxicant action exist within the female and male gonads.

Abstract

Sodium fluoride (NaF), in addition to preventing dental decay may negatively affect the body. The aim of this study was to examine the effect of a 6 h in vitro treatment of gonads isolated from 14-day-old chicken embryos with NaF at doses of 1.7 (D1), 3.5 (D2), 7.1 (D3), and 14.2 mM (D4). The mRNA expression of luteinizing hormone receptor (LHR), follicle-stimulating hormone receptor (FSHR), estrogen receptors (ESR1 and ESR2), progesterone receptor (PGR), and the immunolocalization of progesterone receptors were examined in the tissue. In the ovary, the expression of FSHR and LHR increased following the NaF treatment. In the case of FSHR the highest stimulatory effect was noticed in the D2 group, while the expression of LHR increased in a dose-dependent manner. A gradual increase in ESR1 and PGR mRNA levels was also observed in the ovary following the NaF treatment, but only up to the D3 dose of NaF. The highest ESR2 level was also found in the D3 group. In the testes, the lowest dose of NaF significantly decreased the expression of FSHR, ESR1, ESR2, and PGR. On the other hand, an increase in PGR expression was observed in the D3 group. The expression of LHR in the testes was not affected by the NaF treatment. Immunohistochemical analysis showed that NaF exposure increased progesterone receptor expression in the ovarian cortex, while it decreased its expression in the testes. These results reveal that NaF may disturb the chicken embryonic development and different mechanisms of this toxicant action exist within the females and males.

Hypertension and reproductive dysfunction: a possible role of inflammation and inflammation-associated lymphangiogenesis in gonads

Hypertension is one of the most prevalent diseases that leads to end organ damage especially affecting the heart, kidney, brain, and eyes. Numerous studies have evaluated the association between hypertension and impaired sexual health, in both men and women. The detrimental effects of hypertension in men includes erectile dysfunction, decrease in semen volume, sperm count and motility, and abnormal sperm morphology. Similarly, hypertensive females exhibit decreased vaginal lubrication, reduced orgasm, and several complications in pregnancy leading to fetal and maternal morbidity and mortality. The adverse effect of hypertension on male and female fertility is attributed to hormonal imbalance and changes in the gonadal vasculature. However, mechanistic studies investigating the impact of hypertension on gonads in more detail on a molecular basis remain scarce. Hence, the aim of the current review is to address and summarize the effects of hypertension on reproductive health, and highlight the importance of research on the effects of hypertension on gonadal inflammation and lymphatics.

Differential Disrupting Effects of Prolonged Low-Dose Exposure to Dichlorodiphenyltrichloroethane on Androgen and Estrogen Production in Males

Dichlorodiphenyltrichloroethane (DDT) is the most widespread, persistent pollutant and endocrine disruptor on the planet. Although DDT has been found to block androgen receptors, the effects of its low-dose exposure in different periods of ontogeny on the male reproductive system remain unclear. We evaluate sex steroid hormone production in the pubertal period and after maturation in male Wistar rats exposed to low doses of o,p'-DDT, either during prenatal and postnatal development or postnatal development alone. Prenatally and postnatally exposed rats exhibit lower testosterone production and increased estradiol and estriol serum levels after maturation, associated with the delayed growth of gonads. Postnatally exposed rats demonstrate accelerated growth of gonads and higher testosterone production in the pubertal period. In contrast to the previous group, they do not present raised estradiol production. All of the exposed animals exhibit a reduced conversion of progesterone to 17OH-progesterone after sexual maturation, which indicates putative attenuation of sex steroid production. Thus, the study reveals age-dependent outcomes of low-dose exposure to DDT. Prenatal onset of exposure results in the later onset of androgen production and the enhanced conversion of androgens to estrogens after puberty, while postnatal exposure induces the earlier onset of androgen secretion.

Selenium in Endocrinology-Selenoprotein-Related Diseases, Population Studies, and Epidemiological Evidence

Selenium (Se), apart from iodine, iron, and calcium, is one of the nutrient-derived key elements strongly affecting the endocrine system. However, no specific hormonal "feedback" regulation for Se status has yet been identified, in contrast to the fine-tuned hormone network regulating Ca2+ and phosphate balance or hepcidin-related iron status. Since its discovery as an essential trace element, the effects of Se excess or deficiency on the endocrine system or components of the hypothalamic-pituitary-periphery feedback circuits, the thyroid hormone axis, glucoregulatory and adrenal hormones, male and female gonads, the musculoskeletal apparatus, and skin have been identified. Analysis of the Se status in the blood or via validated biomarkers such as the hepatically derived selenoprotein P provides valuable diagnostic insight and a rational basis for decision making on required therapeutic or preventive supplementation of risk groups or patients. Endocrine-related epidemiological and interventional evidence linking Se status to beneficial or potentially adverse actions of selected selenoproteins mediating most of the (patho-) physiological effects are discussed in this mini-review. Autoimmune thyroid disease, diabetes and obesity, male fertility, as well as osteoporosis are examples for which observational or interventional studies have indicated Se effects. The currently prevailing concept relating Se and selenoproteins to "oxidative stress," reactive oxygen species, radical hypotheses, and related strategies of pharmacological approaches based on various selenium compounds will not be the focus. The crucial biological function of several selenoproteins in cellular redox-regulation and specific enzyme reactions in endocrine pathways will be addressed and put in clinical perspective.

Transcriptomic analysis of gene expression in normal goat ovary and intersex goat gonad

Intersexuality is a congenital reproductive disorder that usually occurs in hornless goats, hindering breeding of goats with hornless traits and the development of the goat industry. In this study, we aimed to identify differentially expressed genes in intersex and normal goat gonads by comparing gene transcription profiles of intersex and normal goat gonads. As intersex goats are genetically based on females, we chose female goats as controls. The goats in the control group and the experimental group were both over one-year old. We evaluated the anatomical characteristics of the reproductive organs of five intersex goats using histopathological methods. The gonads were found to be ovarian and testicular types. RNA-Seq technology was used to identify differentially expressed genes in gonads and normal goat ovary tissues. Transcription analysis results were verified by qPCR. The results showed that 2,748 DEGs were upregulated and 3,327 DEGs were downregulated in intersex ovaries unlike in controls, whereas 2006 DEGs were upregulated and 2032 DEGs were downregulated in the interstitial testes. Many of these genes play important roles in mammalian sex determination and sex differentiation, such as SOX9, WT1, GATA4, DMRT1, DHH, AMH, CYP19A1 and FST. We found that many DEGs are involved in biological developmental regulation by GO and KEGG enrichment analyses, and that most genes associated with the steroid synthesis pathway were downregulated. The DEGs identified in this study may be involved in the regulation of intersex goat sex determination and differentiation, and may increase our understanding of the molecular mechanisms of mammalian sex differentiation.

Direct and Indirect Effects of Sex Steroids on Gonadotrope Cell Plasticity in the Teleost Fish Pituitary

The pituitary gland controls many important physiological processes in vertebrates, including growth, homeostasis, and reproduction. As in mammals, the teleost pituitary exhibits a high degree of plasticity. This plasticity permits changes in hormone production and secretion necessary to meet the fluctuating demands over the life of an animal. Pituitary plasticity is achieved at both cellular and population levels. At the cellular level, hormone synthesis and release can be regulated via changes in cell composition to modulate both sensitivity and response to different signals. At the cell population level, the number of cells producing a given hormone can change due to proliferation, differentiation of progenitor cells, or transdifferentiation of specific cell types. Gonadotropes, which play an important role in the control of reproduction, have been intensively investigated during the last decades and found to display plasticity. To ensure appropriate endocrine function, gonadotropes rely on external and internal signals integrated at the brain level or by the gonadotropes themselves. One important group of internal signals is the sex steroids, produced mainly by the gonadal steroidogenic cells. Sex steroids have been shown to exert complex effects on the teleost pituitary, with differential effects depending on the species investigated, physiological status or sex of the animal, and dose or method of administration. This review summarizes current knowledge of the effects of sex steroids (androgens and estrogens) on gonadotrope cell plasticity in teleost anterior pituitary, discriminating direct from indirect effects.

Multivariate models for estimating jackass semen production and quality

The purpose of this study was to analyse the effects of season, age, gonad and accessory sex glands on semen characteristics of jackass and to construct multivariate regression models to predict semen quality. In autumn, spring and summer, semen characteristics of 30 sexually mature donkeys (1,014 ejaculations) were analysed to investigate the effect of seasons on semen quality, and gonad and accessory sex gland parameters of 12 jackasses were measured immediately after ejaculation by ultrasonography to investigate the effect of seasons on reproductive organ size. Semen (598 ejaculates), gonad and accessory sex gland parameters of 40 jackasses aged between 3 and 7 years were analysed in autumn to investigate the effects of age and reproductive organ size on semen quality and to construct multivariate models. To verify the accuracy of the models, semen (476 ejaculates), gonad and accessory sex gland parameters of 20 jackasses were measured from March to June. Results revealed that semen, gonad and accessory sex gland parameters were not affected by season and age. Progressive motility (PM) was positively correlated with long axis of the spermatic cord (LASC) and negatively correlated with percentages of sperm abnormality (PSA). Total sperm count (TSC) was positively correlated with testis circumferences (TC) and cross-sectional area of cauda epididymis (CSACE). TC, CSACE, LASC and PSA were included into multivariate models to predict PM, TSC and functional sperm count (FSC) in 20 jackasses (PM = 72.332 + 0.428 LASC - 0.441 PSA; TSC = -169.929 + 8.728 TC + 0.253 CSACE; FSC = -206.645 + 8.788 TC + 0.258 CSACE). The predicted and observed values corresponded well. In conclusion, the tested models can be used for predicting semen quality of donkey.

The Central Role of Cadherins in Gonad Development, Reproduction, and Fertility

Cadherins are a group of membrane proteins responsible for cell adhesion. They are crucial for cell sorting and recognition during the morphogenesis, but they also play many other roles such as assuring tissue integrity and resistance to stretching, mechanotransduction, cell signaling, regulation of cell proliferation, apoptosis, survival, carcinogenesis, etc. Within the cadherin superfamily, E- and N-cadherin have been especially well studied. They are involved in many aspects of sexual development and reproduction, such as germline development and gametogenesis, gonad development and functioning, and fertilization. E-cadherin is expressed in the primordial germ cells (PGCs) and also participates in PGC migration to the developing gonads where they become enclosed by the N-cadherin-expressing somatic cells. The differential expression of cadherins is also responsible for the establishment of the testis or ovary structure. In the adult testes, N-cadherin is responsible for the integrity of the seminiferous epithelium, regulation of sperm production, and the establishment of the blood-testis barrier. Sex hormones regulate the expression and turnover of N-cadherin influencing the course of spermatogenesis. In the adult ovaries, E- and N-cadherin assure the integrity of ovarian follicles and the formation of corpora lutea. Cadherins are expressed in the mature gametes and facilitate the capacitation of sperm in the female reproductive tract and gamete contact during fertilization. The germ cells and accompanying somatic cells express a series of different cadherins; however, their role in gonads and reproduction is still unknown. In this review, we show what is known and unknown about the role of cadherins in the germline and gonad development, and we suggest topics for future research.

Bioaccumulation of mercury in Haemulopsis elongatus and Pomadasys macracanthus from the SE Gulf of California: condition indexes and health risk assessment

Mercury (Hg) was measured in the muscle, liver, and gonads of Haemulopsis elongatus and Pomadasys macracanthus from Mazatlán (SE Gulf of California) to determine the relationships of the hepatosomatic index (HSI) and gonadosomatic index (GSI) of fish with Hg concentrations in the corresponding tissues. Health risk to consumers was assessed by using the hazard quotient (HQ), considering the average rate of fish consumption in Mexico and Hg concentration in the edible tissue. In H. elongatus, the highest Hg levels were measured in the liver (3.748 μg g^-1); in P. macracanthus, the highest Hg concentration was quantified in the muscle (0.574 μg g^-1). In P. macracanthus, the HSI was negatively correlated with Hg concentration in the liver; in H. elongatus, there was also a negative relationship between Hg levels in gonads and the GSI. Mean HQ values in Haemulopsis elongatus (0.005) and Pomadasys macracanthus (0.002) were below the value (HQ ≥ 1) of concern. The significant reduction of HSI and GSI with Hg increase in the liver and gonads may suggest that Hg bioaccumulation in these fish shows adverse physiological effects. Though HQ values in both species were below the unit, i.e., the consumption of the muscle from this species does not represent a health risk, it is necessary to carry out surveys of fish consumption rates in coastal areas of Mexico to do a more precise health risk assessment associated to Hg intake.

Melatonin on hypothyroidism and gonadal development in rats: a review

We evaluated the evidence in research on the effects of melatonin on hypothyroidism and gonadal development. According to the World Health Organization, thyroid disorders due to iodine deficiency affect about 740 million people worldwide. Hypothyroidism is a thyroid dysfunction characterized by hypometabolism of the gland, with reduced or physiologically normal T3 and T4 serum levels, and high TSH level. This disorder occurs mainly in adult women in the reproductive phase, with a prevalence of 2% among the world's female population, with profound repercussions on gestation and fetal formation. During the gestational period, the thyroid is initially stimulated by high concentrations of human chorionic gonadotrophin; thus, maintaining maternal euthyroidism during pregnancy and lactation is fundamental for fetal growth and development. Besides, the hormones produced by this gland are involved in the formation of various organs, such as the skin, brain and gonads. Hypothyroidism is associated with several menstrual abnormalities, anovulation and hyperprolactinemia, resulting in a high rate of abortions, premature births, placental rupture, and weight-related neonatal deficits. In addition, there are studies showing that hypothyroidism can affect ovarian morphology (number of ovarian follicles) and testicular morphology (changes in the testicular-lumen epithelium). Melatonin is a hormone known to modulate the estrous cycle and pregnancy, and studies show that the exogenous application of melatonin increased T4 levels in female rats and controlled the decrease in T3 serum levels, reverting the sigs of hypothyroidism.

SARS-CoV-2 (COVID-19) and the Endocrine System

As SARS-CoV-2 (COVID-19) overtakes the world, causing moderate to severe disease in about 15% of infected patients, COVID-19 is also found to have widespread effects throughout the body with a myriad of clinical manifestations including the endocrine system. This manuscript reviews what is known about the impact of COVID-19 on the pathophysiology and management of diabetes (both outpatient and inpatient) as well as pituitary, adrenal, thyroid, bone, and gonadal function. Findings in this area are evolving, and long-term effects of infection remain an active area of further research.

Endocrine Involvement in COVID-19: Mechanisms, Clinical Features, and Implications for Care

Coronavirus 2019 (COVID -19) has rapidly emerged as a global pandemic with multi-system involvement. Involvement of the endocrine system is expected in COVID-19 as the interplay between severe acute respiratory syndrome corona virus-2 (SARS CoV-2) and the endocrine system occurs at multiple levels. The widespread presence of ACE-2 receptors on various tissues suggests scope for direct viral infection. The interactions via the activation of inflammatory mediators and indirect immune-mediated damage are also postulated. Evidence so far suggests that COVID-19 can cause functional hypopituitarism by direct and indirect effects on the hypothalamo-pituitary axis resulting in inappropriate adrenal response to stress. Several reports highlight possible immune-mediated damage to thyroid glands resulting in subacute thyroiditis. COVID-19 is implicated in precipitating hyperglycemia in known diabetics and uncovering insulin resistance in those previously undiagnosed. COVID-19 has also been shown to trigger Type 1 Diabetes with ketosis. Various mechanisms including direct virus-induced beta cell apoptosis and immune-mediated beta-cell damage have been demonstrated. The presence of virus in semen has unclear clinical significance at present. In this mini-review summarize the endocrine manifestations reported so far in COVID-19 disease and explore mechanisms to decipher how SARS CoV-2 may affect various endocrine organs.

Impact of Oral Supplementation of Different Levels of Tamoxifen on Productive and Reproductive Efficiencies and Carcass Traits of Avian48 and Arbor Acres Broilers

This research was aimed at estimating the effect of oral supplementation of Tamoxifen on productive efficiency, carcass characteristics, hormonal profile and gonadal structure of two broiler breeds. One hundred and eighty chicks of each breed of Avian48 and Arbor Acres were divided into three groups: control group; TAM10 group, supplied with 10 mg Tamoxifen/kg of body weight at 3, 5, 7 and 9 days of life; and TAM20 group, supplied at the same intervals with 20 mg Tamoxifen/kg of body weight. Both levels of Tamoxifen improved productive performance at early ages, but Arbor Acres produced better results with TAM20 levels than TAM10, while Avian48 breeds reacted adversely. On the contrary, Tamoxifen supplementation significantly decreased feed intake and feed conversion (after the first two weeks of life) compared to control with a higher level of decrease reported for TAM20 treatments than TAM10 and for Arbor Acres compared to Avian48 breed. Carcass traits were not affected significantly with Tamoxifen supplementation compared to control although Arbor Acres responded better to TAM20 and Avian48 for TAM10. With regard to the effect of Tamoxifen (TAM) on sex hormones, it could be concluded that TAM10 treatments showed a stimulating effect on the level of such hormones as compared with the TAM20 group with the most favourable results being clearly detectable in 42-day-old birds although both concentrations of Tamoxifen did not differ significantly from control. However, treatment of broiler chickens with Tamoxifen in different doses caused a gradual decrease in follicle production rate and eventually led to an increase of the atretic follicles in different stages of atresia. Finally, we can conclude that Tamoxifen supplementation can improve performance and carcass efficiency of broilers without changing the hormonal profile, however much research is required to estimate the best concentration required for each breed.

RNA-Seq transcriptome data of undifferentiated and differentiated gonads of Siberian sturgeon

RNA-Seq transcriptome data from twenty Siberian sturgeon gonads at different developmental stages is described: ten undifferentiated gonads, six gonads of immature males and four gonads from immature females. Siberian sturgeon, Acipenser baerii, is long-lived, late-maturing fish farmed in 50 countries but its production remains on a craftsman scale when compared to industrial species. Sturgeon genetic and physiological studies are less developed than for industrial fish. The data presented hereafter enables fundamental studies on the regulatory mechanisms of sturgeon gonad development, which can further be applied both in aquaculture and in fundamental research.

A rare enzymatic defect, true isolated 17,20-lyase deficiency leading to endocrine disorders and infertility: case report

The cytochrome P450 17A1 catalyzes the formation of 17-hydroxysteroids and 17-ketosteroid. Most defects in CYP17A1 impair both enzymatic activities and cause a combined 17α-hydroxylase/17,20-lyase deficiency, which impairs hormone production (cortisol and sex steroids), sexual development, and puberty. Isolated 17,20-lyase deficiency is usually defined by evidently normal activity of 17α-hydroxylase with a dramatic decline of 17,20-lyase activity or complete inactivity. The changes in enzyme activity lead to a lack in the production of sex steroids with normal levels of glucocorticoid and mineralocorticoid hormones. A 24-years-old married woman, as a product of a consanguineous marriage, presented with infertility and a background marked by primary amenorrhea. Laboratory data showed low normal serum cortisol levels and low levels of 17-hydroxyprogesterone. Also, her adrenal androgens were low but estradiol was normal. The chromosomal investigation uncovered a male karyotype of 46, XY. These clinical and laboratory evidence confirm the determination of an isolated 17,20-lyase deficiency in a genotypic male.

Disorders of Sex Development-Novel Regulators, Impacts on Fertility, and Options for Fertility Preservation

Disorders (or differences) of sex development (DSD) are a heterogeneous group of congenital conditions with variations in chromosomal, gonadal, or anatomical sex. Impaired gonadal development is central to the pathogenesis of the majority of DSDs and therefore a clear understanding of gonadal development is essential to comprehend the impacts of these disorders on the individual, including impacts on future fertility. Gonadal development was traditionally considered to involve a primary 'male' pathway leading to testicular development as a result of expression of a small number of key testis-determining genes. However, it is increasingly recognized that there are several gene networks involved in the development of the bipotential gonad towards either a testicular or ovarian fate. This includes genes that act antagonistically to regulate gonadal development. This review will highlight some of the novel regulators of gonadal development and how the identification of these has enhanced understanding of gonadal development and the pathogenesis of DSD. We will also describe the impact of DSDs on fertility and options for fertility preservation in this context.

Effect of melatonin on gonad and thyroid development of offspring of hypothyroid pregnant rats

We investigated the effects of melatonin on rats with induced hypothyroidism during gestation as well as its effect on the development of the gonads of their offspring. Fifteen pregnant rats were divided into three groups: GC, rats without induced hypothyroidism; GH, rats with induced hypothyroidism; GHM, rats with induced hypothyroidism plus melatonin. Hypothyroidism was induced by oral administration of 6-propyl-2-thiouracil and melatonin was applied subcutaneously. Treatments were performed during gestation and lactation. For the matrices, we evaluated the number of pups, body weight gain, ovarian weight, thyroid weight, organosomatic index, thyroid stimulating hormone (TSH) dose and thyroid morphometry. For the pups, weight gain, TSH, weight, morphometry of the gonads and organosomatic index were analyzed, as well as the cell proliferation index. TSH was elevated only in the matrices of GH animals. Melatonin prevented reduction of ovarian and thyroid weight, number of pups, follicular diameter and thyroid epithelial proportion of the matrices with hypothyroidism. The offspring of rats of the GH group exhibited less body weight gain, gonad and thyroid weight, and gonad cell proliferation index compared to the offspring born of rats of the GC and GHM groups. Melatonin prevented the effects of maternal hypothyroidism on the offspring of rats.