Gonadal Sex Research Articles

Aging is associated with sex-specific alteration in the expression of genes encoding for neuroestradiol synthesis and signaling proteins in the mouse trigeminal somatosensory input

Pain perception is influenced by sex and aging, with previous studies indicating the involvement of aromatase, the estradiol synthase enzyme, in regulating pain perception. Previous research has established the presence of aromatase in dorsal root ganglia sensory neurons and its role in modulating pain perception. The present study aims to explore the implications of aging and sex on the expression of aromatase and estrogen receptors in the trigeminal ganglion. The study examined mRNA levels of aromatase, ERs, and the androgen receptor (AR) in the trigeminal ganglion of 3-month-old and 27-month-old male and female mice, as well as 3-month-old mice from the four-core genotype (FCG) transgenic model. The latter facilitates the assessment of gonadal hormone and sex chromosome implications for sex-specific traits. Aromatase localization in the ganglion was further assessed through immunohistochemistry. Aromatase immunoreactivity was observed for the first time in sensory neurons within the trigeminal ganglion. Trigeminal ganglion gene expressions were detected for aromatase, ERs, and AR in both sexes. Aromatase, ERβ, and GPER gene expressions were higher in young males versus young females. Analyses of the FCG model indicated that sex differences depended solely on gonadal sex. The aging process induced an enhancement in the expression of aromatase, ERs, and AR genes across both sexes, culminating in a reversal of the previously observed gender-based differences. the potential impact of estrogen synthesis and signaling in the trigeminal ganglion on age and sex differences warrants consideration, particularly in relation to trigeminal sensory functions and pain perception.Graphical abstractAge and gonadal sex influence ERs, AR, and ARO levels in the trigeminal ganglion. Although somatosensory perception shows a decline in the elderly, the incidence of trigeminal neuralgia intensifies in aged adults and is predominantly prevalent in women relative to men. The increased expression of aromatase and estrogen receptors in aged female animals suggests that the modulatory influence that neuroestradiol exerts over the trigeminal somatosensory input, inclusive of pain, undergoes changes in elderly male and female individuals in a sex-specific manner.

Genetic hypogonadal (Gnrh1hpg) mouse model uncovers influence of reproductive axis on maturation of the gut microbiome during puberty.

The gut microbiome plays a key role in human health and gut dysbiosis is linked to many sex-specific diseases including autoimmune, metabolic, and neurological disorders. Activation of the hypothalamic-pituitary-gonadal (HPG) axis during puberty leads to sexual maturation and development of sex differences through the action of gonadal sex steroids. While the gut microbiome also undergoes sex differentiation, the mechanisms involved remain poorly understood. Using a genetic hypogonadal (hpg) mouse model, we sampled the fecal microbiome of male and female wild-type and hpg mutant mice before and after puberty to determine how microbial taxonomy and function are influenced by age, sex, and the HPG axis. We showed that HPG axis activation during puberty is required for sexual maturation of the gut microbiota composition, community structure, and metabolic functions. We also demonstrated that some sex differences in taxonomic composition and amine metabolism developed independently of the HPG axis, indicating that sex chromosomes are sufficient for certain sex differences in the gut microbiome. In addition, we showed that age, independent of HPG axis activation, led to some aspects of pubertal maturation of the gut microbiota community composition and putative functions. These results have implications for microbiome-based treatments, indicating that sex, hormonal status, and age should be considered when designing microbiome-based therapeutics.

Lipidomics reveals ceramide biomarkers for detecting central precocious puberty in girls

BackgroundPubertal timing is modulated by complex interactions between the pituitary and gonadal sex steroid hormones. Evidence indicates that sphingolipids are involved in the biosynthesis of steroid hormones at multiple levels. MethodThis study recruited adolescent female patients from pubertal and pediatric endocrine clinics in Northern and Southern Taiwan from the Taiwan Puberty Longitudinal Study. A total of 112 plasma samples (22 healthy control, 29 peripheral precocious puberty (PPP), and 61 CPP samples) were collected. We extracted lipids from the plasma samples using the modified Folch method. The un-targeted ultrahigh-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was employed for the lipid analysis. ResultsWe identified sphingolipid-linked metabolites, including Cer(18:0/15:0), Cer(18:1/16:0), and Cer(18:1/26:0) as candidate biomarkers for distinguishing girls with CPP from the control group by using an excellent discrimination model (AUC = 0.964). Moreover, Cer(18:0/22:0) and Cer(d18:0/18:1) were identified as potential biomarkers of PPP, with an AUC value of 0.938. Furthermore, CerP(18:1/18:0) was identified as the sole candidate biomarker capable of differentiating CPP from PPP. ConclusionsThe biomarkers identified in this study can facilitate the accurate detection of CPP in girls, provide insights into lipid-linked pathophysiology, and present a novel method of monitoring the progression of this disorder.

A New Investigation to Discriminate Sexes in Alive Nile Tilapia (Oreochromis niloticus) Using Cyp19a1a and Dmrt1 Gene Expression in Tail Fin Tissues

The Nile Tilapia (Oreochromis niloticus), a gonochoristic teleost fish with a XX/XY sex-determination system, is an ideal model for investigating gonadal sex differentiation. During gonadal differentiation, the expression of cyp19a1a in XX gonads and dmrt1 in XY gonads are required for undifferentiated tissues to develop into ovary or testis. In this study, quantitative real-time RT-PCR assessed the expression of cyp19a1a and dmrt1 genes in gonads and tail fin tissues. Differences in gene expression mean among sexually differentiated fish were analyzed using two-way analysis of variance (ANOVA) and validation of mixed model using discriminant analysis (DA) for morphometric traits and the gene expression in gonads and tail fin tissues used to validate and utilize them in discriminating sexes in sex-differentiated Nile Tilapia fish. The results revealed that, cyp19a1a gene expression in female ovaries was more significant than dmrt1 in male testis. In the other hand, the dmrt1 gene expression in the tail fin was higher in males than females. Both, cyp19a1a and dmrt1 genes, can discriminate fish sexes by 100% by using their expression in tail fin tissues. In conclusion, the cyp19a1a and dmrt1 genes could be used as a genetic marker to discriminate between the Nile Tilapia sexes, whereas used as an indicator for ovarian or testis differentiation in sexually differentiated Nile Tilapia using tail fin tissues. It is worth mentioning that this is the first investigation for using cyp19a1a and dmrt1 genes from Nile Tilapia tail fin tissues in sex determination.

Pure 46, XY gonadal dysgenesis and 46, XY complete androgen insensitivity syndrome: A case report.

Disorders of sex development (DSD) are congenital conditions characterized by atypical development of chromosomal, gonadal, and phenotypic sex. 46, XY DSD can result from disorders of testicular development or androgen synthesis. We present 2 rare cases of 46, XY DSD, specifically XY pure gonadal dysgenesis and complete androgen insensitivity syndrome. Both cases underwent prophylactic gonadectomy due to the elevated risk of gonadal malignancy. Bilateral gonadoblastoma and dysgerminoma were diagnosed on one side, while Leydig cell hyperplasia and only Sertoli cells were diagnosed in the seminiferous tubules on both sides. The normal menstruation for the pure gonadal dysgenesis patient only as CAIS patients never menstruate. Estrogen replacement therapy was administered periodically to promote the development of secondary sexual characteristics and menstruation in pure gonadal dysgenesis case, as well as to prevent osteoporosis. Follow-up examinations revealed no tumor recurrence, and the patient with Swyer syndrome had regular menstrual cycles. Laparoscopic bilateral prophylactic gonadectomy and long-term hormone therapy with patient counseling and support are recommended.

Molecular characterization and expression analysis of thyroid hormone receptors in protogynous rice field eel, Monopterus albus.

Thyroid hormones (THs) play important roles in growth, development, morphogenesis, reproduction, and so on. They are mainly meditated by binding to thyroid hormone receptors (TRs) in vertebrates. As important members of the nuclear receptor superfamily, TRs and their ligands are involved in many biological processes. To investigate the potential roles of TRs in the gonadal differentiation and sex change, we cloned and characterized the TRs genes in protogynous rice field eel (Monopterus albus). In this study, three types of TRs were obtained, which were TRαA, TRαB and TRβ, encoding preproproteins of 336-, 409- and 415-amino acids, respectively. Multiple alignments of the three putative TRs protein sequences showed they had a higher similarity. Tissue expression analysis showed that TRαA mainly expressed in the gonad, while TRαB and TRβ in the brain. During female-to-male sex reversal, the expression levels of all the three TRs showed a similar trend of increase followed by a decrease in the gonad. Intraperitoneal injection of triiodothyronine (T3) stimulated the expression of TRαA and TRαB, while it had no significant change on the expression of TRβ in the ovary. Gonadotropin-releasing hormone analogue (GnRHa) injection also significantly upregulated the expression levels of TRαA and TRαB after 6 h, while it had no significant effect on TRβ. These results demonstrated that TRs were involved in the gonadal differentiation and sex reversal, and TRα may play more important roles than TRβ in reproduction by the regulation of GnRHa in rice field eel.

Gonadal sex and chromosome complement influence the gut microbiome in a mouse model of allergic airway inflammation.

Evidence abounds that gut microbiome components are associated with sex disparities in the immune system. However, it remains unclear whether the observed sex disparity in asthma incidence is associated with sex-dependent differences in immune-modulating gut microbiota, and/or its influence on allergic airway inflammatory processes. Using a mouse model of house dust mite (HDM)-induced allergic inflammation and the four core genotypes (FCGs) model, we have previously reported sex differences in lung inflammatory phenotypes. Here, we investigated associations of gut microbiomes with these phenotypes by challenging FCG mice [mouse with female sex chromosome and male gonad (XXM), mouse with female sex chromosome and female gonad (XXF), mouse with male sex chromosome and male gonad (XYM), and mouse with male sex chromosome and female gonad (XYF); n = 7/group] with HDM (25 μg) or PBS intranasally for 5 wk and collecting fecal samples. We extracted fecal DNA and analyzed the 16S microbiome via Targeted Metagenomic Sequencing. We compared α and β diversity across genotypes and assessed the Firmicutes/Bacteroidetes (F/B) ratio. When comparing baseline and after exposure for the FCG, we found that the gut F/B ratio was only increased in the XXM genotype. We also found that α diversity was significantly increased in all FCG mice upon HDM challenge, with the highest increase in the XXF, and the lowest in the XXM genotypes. Similarly, β diversity of the microbial community was also affected by challenge in a gonad- and chromosome-dependent manner. In summary, our results indicated that HDM treatment, gonads, and sex chromosomes significantly influence the gut microbial community composition. We concluded that allergic lung inflammation may be affected by the gut microbiome in a sex-dependent manner involving both hormonal and genetic influences.NEW & NOTEWORTHY Recently, the gut microbiome and its role in chronic respiratory disease have been the subject of extensive research and the establishment of its involvement in immune functions. Using the FCG mouse model, our findings revealed the influence of gonads and sex chromosomes on the microbial community structure before and after exposure to HDM. Our data provide a potential new avenue to better understand mediators of sex disparities associated with allergic airway inflammation.

46,XX Differences of Sex Development outside congenital adrenal hyperplasia: pathogenesis, clinical aspects, puberty, sex hormone replacement therapy and fertility outcomes.

The term 'differences of sex development' (DSD) refers to a group of congenital conditions that are associated with atypical development of chromosomal, gonadal, and/or anatomical sex. DSD in individuals with a 46,XX karyotype can occur due to fetal or postnatal exposure to elevated amount of androgens or maldevelopment of internal genitalia. Clinical phenotype could be quite variable and for this reason these conditions could be diagnosed at birth, in newborns with atypical genitalia, but also even later in life, due to progressive virilization during adolescence, or pubertal delay. Understand the physiological development and the molecular bases of gonadal and adrenal structures is crucial to determine the diagnosis and best management and treatment for these patients. The most common cause of DSD in 46,XX newborns is congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, determining primary adrenal insufficiency and androgen excess. In this review we will focus on the other rare causes of 46,XX DSD, outside CAH, summarizing the most relevant data on genetic, clinical aspects, puberty and fertility outcomes of these rare diseases.

Biological sex, sex steroids and sex chromosomes contribute to mouse cardiac aging.

After menopause, the incidence of cardiovascular disease rapidly rises in women. The disappearing protection provided by sex steroids is a consequence of the development of many risk factors. Preclinical studies are necessary to understand better the effects of ovarian hormones loss cardiac aging. To mimic menopause in mice and study its consequences, we delayed ovariectomy at 12 months and followed animals for 12 months. Using RNA sequencing, we investigated changes in the myocardial exome with aging. In addition, with four-core genotypes (FCG) transgenic mice, we studied sex chromosome effects on cardiac aging. Heart weight increased from 3 to 24 months (males + 35%, females + 29%). In males, 75% of this increase had occurred at 12 months; in females, only 30%. Gonadectomy of mice at 12 months blocked cardiac hypertrophy in both sexes during the second year of life. The dosage of the X chromosomes did not influence cardiac growth in young and older mice. We performed an RNA sequencing study in young and old mice. We identified new highly expressed genes modulated during aging (Bdh, Myot, Cpxm2, and Slc38a1). The myocardial exome in older animals displayed few differences related to the animal's sex or the presence or absence of sex steroids for a year. We show that the morphological evolution of the heart depends on the biological sex via gonadal sex hormone actions. The myocardial exome of old male and female mice is relatively similar. Our study emphasizes the need to consider sex steroid effects in studying cardiac aging.

Role of NR5A1 Gene Mutations in Disorders of Sex Development: Molecular and Clinical Features.

Disorders/differences of sex development (DSDs) are defined as broad, heterogenous groups of congenital conditions characterized by atypical development of genetic, gonadal, or phenotypic sex accompanied by abnormal development of internal and/or external genitalia. NR5A1 gene mutation is one of the principal genetic alterations implicated in causing DSD. This review outlines the role of NR5A1 gene during the process of gonadal development in humans, provides an overview of the molecular and functional characteristics of NR5A1 gene, and discusses potential clinical phenotypes and additional organ diseases due to NR5A1 mutations. NR5A1 mutations were analyzed in patients with 46,XY DSD and 46,XX DSD both during the neonatal and pubertal periods. Loss of function of the NR5A1 gene causes several different phenotypes, including some associated with disease in additional organs. Clinical phenotypes may vary, even among patients carrying the same NR5A1 variant, indicating that there is no specific genotype-phenotype correlation. Genetic tests are crucial diagnostic tools that should be used early in the diagnostic pathway, as early as the neonatal period, when gonadal dysgenesis is the main manifestation of NR5A1 mutation. NR5A1 gene mutations could be mainly associated with amenorrhea, ovarian failure, hypogonadism, and infertility during puberty. Fertility preservation techniques should be considered as early as possible.

Transcriptome profile of sex-related gene expression and effects of cyp19a1 siRNA-silencing on sex differentiation and determination in yellow perch

In this study, we first sequenced the whole genome of the yellow perch (YP, Perca favencens) and screened transcripts of brain, liver, and gonadal tissues from fish of different sexes. By comparing known female sex-related genes in fish such as cyp19a1 and dmrt1 with YP genome, we obtained full-length sequences through genomic homology analysis. Then an experiment was conducted to evaluate the effects of cyp19a1-siRNA interference on gonadal development and sex differentiation and determination in YP. Transcriptome analysis revealed that the gonadal tissue of female YP exhibited predominantly and differentially up-regulated expression of genes than males, and cyp19a1 was predominantly expressed in the gonads while cyp19a2 showed predominant expression in the brain. KEGG pathway enrichment analysis illustrated the metabolic pathways of the top 25 enriched genes and confirmed CYP19 (P450) pathway in YP. For the cyp19a1-siRNA interference experiment, four intermittent in vivo injections of siRNA were administered to interfere with cyp19a1 gene expression in an all-female group of YP. The results collected at 180 dph revealed that the siRNA interference resulted in an incomplete masculinization and hermaphroditism of all-female monosex YP, displaying the presence of male spermatocytes along with female oocytes. In contrast, tissues from the blank control and negative control groups only contained oocytes. The appearance of the gonads in the experimental group appeared more irregular, lacking the smooth surface and typical histoarchitecture observed in the blank control and negative control groups. In addition, the cyp19a1-siRNA treatment group had significantly (P < 0.05) lower body weight than the control groups, indicating that the interference with cyp19a1 might have affected the expression of estrogen, leading to a trend similar to the growth of males; similarly, the gonad weight and GSIs of the cyp19a1 group were significantly (P < 0.05) lower than those in the control groups, suggesting that the cyp19a1-siRNA interference might have led to a trend of male type of gonadal development. Meanwhile, the treatment group had significantly (P < 0.05) higher HSI and VSI levels compared to control groups, indicating that stimulation of external siRNA might have resulted in more vigorous liver metabolism processes. Furthermore, the expression level of the dmrt1 in the treatment group was significantly (P < 0.05) upregulated compared to the control groups, suggesting the correlation roles between these two genes in the regulation of sex development. The findings provide valuable insights for future research into the underlying mechanisms involved and hold significant promise for sex control in aquaculture.

Abstract 125: The X Chromosome Gene Kdm6a Confers Sex Differences In Mature Adipocyte Function Impacting Cardiometabolic Health

Biological sex impacts cardiovascular disease and other metabolic conditions that increase disease risk, including obesity. Physiological sex differences are determined by two components of sex: gonadal hormones and sex chromosome complement. Using mouse models to dissociate gonadal sex from chromosomal sex, we have identified sex chromosome-dependent regulation of circulating lipoproteins, atherosclerosis, and adiposity. Specifically for adiposity, mice with two X chromosomes had higher body weight gain compared to mice with XY sex chromosomes in the presence of ovaries or testes. In cells with XX chromosome complement, specific X chromosome genes escape X inactivation, which leads to higher expression in XX (female) compared to XY (male) tissues. We identified an X escape gene, Kdm6a , that encodes a histone demethylase enzyme and impacts adiposity by altering the function of mature adipocytes. Mice with mature adipocyte-specific Kdm6a reduction (Ad- Kdm6a -/- ) had lower body weight and adiposity compared to wildtype females. The white adipose triglyceride pool was altered with higher unsaturated and long chain fatty acids in Ad- Kdm6a -/- mice compared to wildtype mice. Furthermore, siRNA knockdown of Kdm6a in cultured adipocytes altered lipid metabolism with reduced lipid droplet size. Given that KDM6A is a histone demethylase, we assessed the Kdm6a dosage effect on adipocyte gene expression and histone modifications across the genome. Differential gene expression associated with lipid homeostasis was identified in Ad- Kdm6a -/- mice and in cultured adipocytes with Kdm6a knockdown compared to controls. KDM6A genomic targets and resultant histone modifications were identified in cultured adipocytes using CUT&amp;RUN. We conclude that differential gene dosage of Kdm6a between female and male tissues is a determinant of adipose sex differences through modulation of histone modifications and gene expression. This leads to effects on adipocyte lipid composition and tissue mass, which impacts susceptibility to obesity and metabolic disease.

Identification and functional analysis of a rare variant of gene DHX37 in a patient with 46,XY disorders of sex development.

46,XY sex reversal 11 (SRXY11) [OMIM#273250] is characterized by genital ambiguity that may range from mild male genital defects to gonadal sex reversal in severe cases. DHX37 is an RNA helicase that has recently been reported as a cause of SRXY11. So far, a total of 21 variants in DHX37 have been reported in 58 cases with 46,XY disorders of sex development (DSD). Whole exome sequencing (WES) was conducted to screen for variations in patients with 46,XY DSD. The subcellular localization of mutant DHX37 proteins was detected by immunofluorescence. And the levels of mutant DHX37 proteins were detected via Western blotting. A novel pathogenic variant of DHX37 was identified in a patient with 46,XY DSD c.2012G > C (p.Arg671Thr). Bioinformatics analysis showed that the protein function of the variant was impaired. Compared with the structure of the wild-type DHX37 protein, the number of hydrogen bonds and interacting amino acids of the variant protein were changed to varying degrees. Invitro assays revealed that the variant had no significant effect on the intracellular localization of the protein but significantly reduced the expression level of the protein. Our finding further expands the spectrum of the DHX37 variant and could assist in the molecular diagnosis of 46,XY DSD patients.

Estetrol/drospirenone versus 17α-ethinylestradiol/drospirenone: An extended one generation test to evaluate the endocrine disruption potential on zebrafish (Danio rerio)

Combined oral contraceptives, comprising of both an oestrogen and a progestin component, are released in aquatic environments and potentially pose a risk to aquatic wildlife by their capacity to disrupt physiological mechanisms.In this study, the endocrine disruptive potential of two mixtures, 17α-ethinylestradiol (EE2), a synthetic oestrogen, or estetrol (E4), a natural oestrogen, with the progestin drospirenone (DRSP) have been characterised in three generations of zebrafish, according to an adapted Medaka Extended One Generation Reproduction Test. Zebrafish (Danio rerio) were exposed to a range of concentrations of EE2/DRSP and E4/DRSP (∼1×, ∼3×, ∼10× and ∼30× predicted environmental concentration, PEC). Survival, growth, hatching success, fecundity, fertilisation success, vitellogenin (VTG), gonad histopathology, sex differentiation, and transcriptional analysis of genes related to gonadal sex steroid hormones synthesis were assessed.In the F0 generation, exposure to EE2/DRSP at ∼10 and ∼30× PEC decreased fecundity and increased male VTG concentrations. The highest concentration of EE2/DRSP also affected VTG concentrations in female zebrafish and the expression of genes implicated in steroid hormones synthesis. In the F1 generation, sex determination was impaired in fish exposed to EE2/DRSP at concentrations as low as ∼3× PEC. Decreased fecundity and fertility, and abnormal gonadal histopathology were also observed. No effects were observed in the F2 generation. In contrast, E4/DRSP induced only minor histopathological changes and an increase in the proportion of males, at the highest concentration tested (∼30× PEC) in the F1 generation and had no effect on hatching success of F2 generation.Overall, this study suggests that the combination E4/DRSP has a more favourable environmental profile than EE2/DRSP.

Completely blocking the feminization by replacing Limnodilus spp. with Artemia salina to feeding XY Zig-zag eel (Mastacembelus armatus)

Zig-zag eel (Mastacembelus armatus), with male growing faster and larger than female, is a popular farmed fish in China due to its delicious taste and rich nutritional value. The culture of mono-sex M. armatus has great value and is the best choice for aquaculture industry. However, the high feminization rate in aquaculture severely limits the application of sex control in the breeding process of M. armatus. In this study, by analyzing the early gonadal development and sex differentiation process, as well as the expression profiles of male and female pathway genes in the early XX and XY gonads, we determined that the critical period for sex differentiation and gonadal differentiation in M. armatus was 10–30 dpf. In addition, we confirmed for the first time that the feminization of M. armatus is related to feeding Limnodilus spp., as only Limnodilus spp. are fed during 10–30 dpf. Replacing Limnodilus spp. with Artemia salina to feed M. armatus fry can completely block the feminization. These results lay a solid foundation for understanding the sex determination mechanism of M. armatus, and the method of blocking the feminization of M. armatus can be used for the development of all-male breeding.

Comparative analysis on growth performance, survival and harvest traits between offspring from wild and mass-selected populations of Crassostrea nippona

Crassostrea nippona has recently been recognized as a preferred alternative to C. gigas in summer due to its firm flesh and high glycogen content. To promote industrial development, the mass selective breeding program was initiated to improve growth performance of C. nippona in 2014. Although a steady genetic gain of approximately 10% for growth traits was achieved in each of the first three generations of the selected strains, little is known about the cumulative genetic progress in desired traits contributed by the selective breeding in the genetic improvement program. In this study, the aquaculture performance of the selected population was comprehensively evaluated by comparing the production performance and reproductive traits of the progeny (WF1 and SF4) from the wild population and the third-generation selected line in commercial farming environments. The results showed that the diameters of eggs from both populations were at similar levels, but the fertilization and hatching rates of the progeny from the selected lines were significantly higher than those of the wild population (P < 0.05). At larval stages, the shell height and cumulative survival rate (CSR) of individuals from SF4 were consistently superior to that of WF1, especially on day 6 post-fertilization, in which CSR of the improved C. nippona was increased by 25.08% compared to that of wild oysters. Meanwhile, a significant 12.10% enhancement in the metamorphosis rate was observed in SF4 when compared with WF1. During the grow-out stage, SF4 displayed distinct advantages in growth performance and survival compared to the wild strain, with 23.19, 33.48, 34.18 and 79.11% improvement in shell height, body weight, CSR and final yield at harvest on day 800, respectively. Meanwhile, relative brood amount (RBA) associated with initial development of offspring was found to be significantly higher in SF4 compared with WF1 (P < 0.05). Remarkably, the gonadal development, sex ratios and biochemical composition of oysters from both populations were at similar levels at final harvest, implying that high-intensity artificial selection had no significant effect on reproductive characteristics and nutritional quality of C. nippona. The encouraging results in the present study suggest that the overall genetic progress contributed by genetic breeding is considerable in the fast-growing strain of C. nippona, and such gains are expected to continue to increase with further selective breeding.

The expression profiles of cyp19a1, sf-1, esrs and gths in the brain-pituitary during gonadal sex differentiation in juvenile Japanese eels

Eels are gonochoristic species whose gonadal differentiation initiates at the yellow eel stage and is influenced by environmental factors. We revealed some sex-related genes were sex dimorphically expressed in gonads during gonadal sex differentiation of Japanese eel (Anguilla japonica); however, the expression of sex-related genes in the brain-pituitary during gonadal sex differentiation in eels is still unclear. This study aimed to investigate the sex-related gene expressions in the brain-pituitary and tried to clarify their roles in the brain and gonads during gonadal sex differentiation. Based on our previous histological study, the control eels developed as males, and estradiol-17β (E2) was used for feminization. Our results showed that during testicular differentiation, the brain cyp19a1 transcripts and aromatase proteins were increased significantly; moreover, the cyp19a1, sf-1, foxl2s, and esrs (except gperb) transcripts in the midbrain/pituitary also were increased significantly. Forebrain gnrh1 transcripts increased slightly during gonadal differentiation of both sexes, but the gnrhr1b and gnrhr2 transcripts in the midbrain/pituitary were stable during gonadal differentiation. The expression levels of gths and gh in the midbrain/pituitary were significantly increased during testicular differentiation and were much higher in males than in E2-feminized females. These results implied that endogenous estrogens might play essential roles in the brain/pituitary during testicular differentiation, sf-1, foxl2s, and esrs may have roles in cyp19a1 regulation in the midbrain/pituitary of Japanese eels. For the GnRH-GTH axis, gths, especially fshb, may be regulated by esrs and involved in regulating testicular differentiation and development in Japanese eels.

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.

Reprograming skin fibroblasts into Sertoli cells: a patient-specific tool to understand effects of genetic variants on gonadal development

BackgroundDisorders/differences of sex development (DSD) are congenital conditions in which the development of chromosomal, gonadal, or anatomical sex is atypical. With overlapping phenotypes and multiple genes involved, poor diagnostic yields are achieved for many of these conditions. The current DSD diagnostic regimen can be augmented by investigating transcriptome/proteome in vivo, but it is hampered by the unavailability of affected gonadal tissue at the relevant developmental stage. We try to mitigate this limitation by reprogramming readily available skin tissue-derived dermal fibroblasts into Sertoli cells (SC), which could then be deployed for different diagnostic strategies. SCs form the target cell type of choice because they act like an organizing center of embryonic gonadal development and many DSD arise when these developmental processes go awry.MethodsWe employed a computational predictive algorithm for cell conversions called Mogrify to predict the transcription factors (TFs) required for direct reprogramming of human dermal fibroblasts into SCs. We established trans-differentiation culture conditions where stable transgenic expression of these TFs was achieved in 46, XY adult dermal fibroblasts using lentiviral vectors. The resulting Sertoli like cells (SLCs) were validated for SC phenotype using several approaches.ResultsSLCs exhibited Sertoli-like morphological and cellular properties as revealed by morphometry and xCelligence cell behavior assays. They also showed Sertoli-specific expression of molecular markers such as SOX9, PTGDS, BMP4, or DMRT1 as revealed by IF imaging, RNAseq and qPCR. The SLC transcriptome shared about two thirds of its differentially expressed genes with a human adult SC transcriptome and expressed markers typical of embryonic SCs. Notably, SLCs lacked expression of most markers of other gonadal cell types such as Leydig, germ, peritubular myoid or granulosa cells.ConclusionsThe trans-differentiation method was applied to a variety of commercially available 46, XY fibroblasts derived from patients with DSD and to a 46, XX cell line. The DSD SLCs displayed altered levels of trans-differentiation in comparison to normal 46, XY-derived SLCs, thus showcasing the robustness of this new trans-differentiation model. Future applications could include using the SLCs to improve definitive diagnosis of DSD in patients with variants of unknown significance.

XX sex chromosome complement modulates immune responses to heat-killed Streptococcus pneumoniae immunization in a microbiome-dependent manner.

Differences in male vs. female immune responses are well-documented and have significant clinical implications. While the immunomodulatory effects of sex hormones are well established, the contributions of sex chromosome complement (XX vs. XY) and gut microbiome diversity on immune sexual dimorphisms have only recently become appreciated. Here we investigate the individual and collaborative influences of sex chromosome complements and gut microbiota on humoral immune activation. Male and female Four Core Genotype (FCG) mice were immunized with heat-killed Streptococcus pneumoniae (HKSP). Humoral immune responses were assessed, and X-linked immune-related gene expression was evaluated to explain the identified XX-dependent phenotype. The functional role of Kdm6a, an X-linked epigenetic regulatory gene of interest, was evaluated ex vivo using mitogen stimulation of B cells. Additional influences of the gut microbiome on sex chromosome-dependent B cell activation was also evaluated by antibiotically depleting gut microbiota prior to HKSP immunization. Reconstitution of the depleted microbiome with short-chain fatty acid (SCFA)-producing bacteria tested the impact of SCFAs on XX-dependent immune activation. XX mice exhibited higher HKSP-specific IgM-secreting B cells and plasma cell frequencies than XY mice, regardless of gonadal sex. Although Kdm6a was identified as an X-linked gene overexpressed in XX B cells, inhibition of its enzymatic activity did not affect mitogen-induced plasma cell differentiation or antibody production in a sex chromosome-dependent manner ex vivo. Enhanced humoral responses in XX vs. XY immunized FCG mice were eliminated after microbiome depletion, indicating that the microbiome contributes to the identified XX-dependent immune enhancement. Reconstituting microbiota-depleted mice with select SCFA-producing bacteria enhanced fecal SCFA concentrations and increased humoral responses in XX, but not XY, FCG mice. However, exposure to the SCFA propionate alone did not enhance mitogenic B cell stimulation in ex vivo studies. FCG mice have been used to assess sex hormone and sex chromosome complement influences on various sexually dimorphic traits. The current study indicates that the gut microbiome impacts humoral responses in an XX-dependent manner, suggesting that the collaborative influence of gut bacteria and other sex-specific factors should be considered when interpreting data aimed at delineating the mechanisms that promote sexual dimorphism.