Reproduction-related Genes Research Articles

Dietary organic acid blend modulates hemato-immunological parameters, digestive and reproductive performances in red tilapia (Oreochromis niloticus × O. mossambicus) broodstock.

This study evaluated the effects of dietary organic acid (OA) blend on hemato-immunological responses, reproduction capacity, gene expression, and histological features of red tilapia (Oreochromis niloticus × O. mossambicus) broodstock. Four diets were formulated, containing 0 (control), 2, 3, and 4g OAs kg-1. The diets were fed to triplicate groups (n = 3) of red tilapia broodstock (75 ± 5.56g( (mean ± standard deviation (SD)) stocked in 10-m3 concrete tanks at a male to female ratio of 1:3, to satiation, twice a day, for 8weeks. At the end of the feeding trial, fish in each tank were collected, counted, and weighed. Blood samples were collected from five fish from each tank and used for the determination of hematological and biochemical parameters. The fish were then dissected to study the reproductive performance and reproduction-related genes. The red blood cells (RBCs), hemoglobin (Hb), packed cell volume (PCV%), mean corpuscular volume (MCV), and lysozyme activity were significantly increased (P < 0.05) with increasing dietary OAs to 4gkg-1. Mean corpuscular hemoglobin (MCH), white blood cells (WBCs), total protein, albumin, and globulin), and digestive enzyme activity values leveled off or slightly decreased (P > 0.05) at OA levels above 3gkg-1. Optimum liver enzyme activity was obtained at 2gkg-1 OA. The reproductive hormones: testosterone (T), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), and progesterone (Prog), organo-somatic index (GSI), reproductive performance, and the expression of reproductive genes (vasa, nanos1a, nanos2, dnd1, pum1, amh, and VTG) exhibited dose-dependent responses (P < 0.05), suggesting that 4g OA kg-1 boosted the optimum reproductive performance. In conclusion, about 2-3g OA kg-1 diet can improve the hemato-biochemical parameters, immune response, antioxidant status, and digestive enzyme activity in red tilapia broodstock, whereas 4gkg-1 could accelerate their reproductive performance through upregulation of reproductive genes.

Effects of cadmium on female Drosophila melanogaster and its transgenerational inheritance effects.

Cadmium (Cd) is a silvery-white and shiny heavy metal that is common in daily life and can adversely affect the development, lifespan, and reproduction of organisms. In this study, Drosophila melanogaster (F0) were cultured from eggs to adults in medium containing different Cd concentrations (0, 2.25, and 4.5mg/kg), and offspring (F1-F4 generations) were cultured in standard medium. The morphology of the ovaries of female flies under Cd stress changed, apoptosis occurred, fertility decreased, and the levels of 20-Hydroxyecdysone and vitellogenin decreased significantly. These changes were more significant under high-concentration treatment. In addition, the inhibitory effects of Cd on reproduction-related genes (spook, phantom, disembodies, shadow, shade, ECR, vg, and Kr-h1) in F0 female flies could transmit to two or three generations. Cd exposure also induced increased expression of miR-927 and mediated its transgenerational inheritance. These results indicate that damage to the ovaries and the changes in related-genes expressions of female flies induced by Cd stress can be transmitted to offspring and may be related to changes in miRNA expression in Drosophila. The transgenerational inheritance effects of heavy metals on organisms and their potential risks to future ecosystems deserve attention and reassess.

Full-length transcriptome analysis of male and female gonads in Japanese Eel (Anguilla japonica)

BackgroundThe Japanese eel (Anguilla japonica) holds significant economic value in East Asia, but limitations in understanding its reproductive biology have hindered advancements in artificial breeding techniques. Previous research has primarily focused on conserved sex differentiation genes, offering limited insights into the broader molecular mechanisms driving gonadal development and sexual dimorphism. To address these limitations, this study aims to investigate key genes and pathways involved in gonadal development through a comprehensive transcriptomic analysis of male and female eel gonads.ResultsPacBio Iso-Seq and Illumina RNA-Seq technologies were combined to conduct a full-length transcriptome analysis of male and female Japanese eel gonads at a post-differentiation, pre-maturation stage. A total of 24,661 unigenes were identified in ovaries and 15,023 in testes, along with genomic regulatory elements such as transcription factors, simple sequence repeats, and long non-coding RNAs. Additionally, 1,210 differentially expressed genes were detected. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed significant pathways involved in cell cycle regulation, metabolic processes, apoptosis, and hormone activity. Notably, several reproductive-related genes, including bambi, ccnb1, cdc20, gdf9, prlh, ccdc39, chrebp, tspo, syce3, and ngb, demonstrated significant dimorphic expression in eel gonads.ConclusionsThis study provides valuable insights into the molecular mechanisms of gonadal differentiation and sexual dimorphism in Japanese eels. The findings expand the genetic resources available for the eel breeding industry and could facilitate the development of improved artificial breeding techniques focused on reproductive development.

Unveiling the impact of polystyrene and low-density polyethylene microplastics on arsenic toxicity in earthworms.

The high global production combined with low recycling rates of polystyrene (PS) and low-density polyethylene (LDPE) contributes to the abundance of these commonly used plastics in soil, including as microplastics (MPs). However, the combined effects of MPs and heavy metals, such as arsenic (As) on earthworms are poorly understood. Here, we show that neither PS nor LDPE altered the effects of As on the survival, growth, and reproduction of the earthworm Eisenia fetida. As stress, both alone and in combination with the MPs, induced DNA damage in coelomocytes. In As-exposed earthworms, PS and LDPE increased the accumulation of reactive oxygen species while the activities of the antioxidant enzymes peroxidase, superoxide dismutase, and catalase were significantly lower under combined PS/LDPE+As exposure than under As exposure alone. As stress alone reduced cocoon production and the mRNA level of the reproduction-related gene ANN whereas As combined with PS/LDPE reduced the mRNA levels of CYP450, an enzyme involved in detoxification. Integrated biomarker response analysis revealed that PS/LDPE did not significantly impact the overall ecotoxicological effects of As exposure on earthworms. This study provides important insights into the potential ecological risks of MPs in heavy-metal-contaminated soil.

Reproductive Toxicity of Nanomaterials Using Silver Nanoparticles and Drosophila as Models.

Reproductive toxicity is of special concern among the harmful effects induced by environmental pollutants; consequently, further studies on such a topic are required. To avoid the use of mammalians, lower eukaryotes like Drosophila are viable alternatives. This study addresses the gap in understanding the link between reproductive adverse outcomes and the presence of pollutants in reproductive organs by using Drosophila. Silver nanoparticles (AgNPs) were selected for their ease of internalization, detection, and widespread environmental presence. Both male and female flies were exposed to AgNPs (28 ± 4 nm, 100 and 400 µg/mL) for one week. Internalization and bioaccumulation of AgNPs in organs were assessed using transmission electron microscopy, confocal microscopy, and inductively coupled plasma mass spectrometry. Substantial accumulation of AgNPs in the gastrointestinal tract, Malpighian tubules, hemolymph, reproductive organs (ovaries and testes), and gametes were observed. The highest AgNP content was observed in testes. Exposure to AgNPs reduced ovary size and fecundity, though fertility and gender ratios of the offspring were unaffected. Significant deregulation of reproductive-related genes was observed, particularly in males. These findings underscore the utility of Drosophila as a model for evaluating reproductive hazards posed by AgNP exposure. The ease of AgNP internalization in Drosophila reproductive targets could be extrapolated to mammalians, raising concerns about the potential impacts of nanoparticle exposure on reproduction toxicity in humans.

Active immunization with a novel recombinant GnRH vaccine inhibits reproductive function in male goats.

Gonadotropin-releasing hormone (GnRH) vaccines have been widely used to effectively inhibit gonadal development and reproductive function. To improve the immunogenicity of GnRH, we developed and evaluated the effects of GnRH6-kisspeptin-CRM197 immunization on the reproductive function in male goats. Thirty 3-month-old male goats (n = 30) were randomly assigned to control, surgical, and immunized groups. The immunized group received a 2 mL injection of the GnRH6-kisspeptin-CRM197 with a booster administered four weeks later. The control group was administered a white oil adjuvant. Blood samples were collected at regular intervals, and at week 20, the animals were euthanized for tissue collection. Serum antibody titers and testosterone levels were measured using ELISA and CLIA, respectively. Testicular parameters and histology were evaluated. The mRNA levels of reproductive-related genes in the HPG axis were measured using RT-qPCR. The results showed that the immunized goats had significantly increased serum GnRH and kisspeptin antibodies (P < 0.05) but decreased testosterone concentrations (P < 0.05) compared to the control group. Testicular size and histology were significantly affected in the immunized group, with notable reductions in testicular weight and dimensions (P < 0.01), and evidence of vacuolar degeneration and suppressed sperm production. The mRNA levels of FSHβ and LHβ in the pituitary, as well as FSHR, LHR, 3βHSD, and 17βHSD in the testis, were significantly lower in the immunized group compared to controls (P < 0.05). These findings suggest that GnRH6-kisspeptin-CRM197 is a safe antigen and a promising immunocastration vaccine with enhanced efficacy.

The fertility recovering from heat stress and interactions of heat shock protein 20 with reproduction-related proteins in Monochamus alternatus.

Due to the rise in global temperatures with climate change, insects, as ectotherms, critically depend on their heat tolerance for survival and reproduction. Heat shock proteins (HSPs) are essential for heat tolerance by averting protein denaturation; however, whether HSPs contribute to reproduction-related heat tolerance remains largely unexplored. The study investigated the reproductive heat tolerance and recovery of Monochamus alternatus, a major forestry pest, in response to heat stress. Alongside impairing the development and viability of reproductive organs and sperm, heat stress was also found to reduce fecundity, fertility, mating, and oviposition behaviors. Remarkably, all reproductive parameters of M. alternatus recovered within 4 weeks postexposure. To investigate the recovery mechanisms, we identified 10 reproduction-related proteins as candidate substrate proteins of an HSP protein in M. alternatus using immunoprecipitation coupled with mass spectrometry analysis. Heat stress inhibited the transcription of these reproduction-related genes, thereby adversely affecting reproductive parameters. However, the induction of HSP20s transcription in response to heat stress appeared to facilitate the refolding of these critical reproduction-related proteins during the recovery phase, thus preventing lasting reproductive damage. Overall, this study suggests that while M. alternatus populations might be vulnerable to climate-induced temperature increases, their fertility can recover, mediated by the interaction of HSPs with reproduction-related genes. These findings offer profound insights into insect heat tolerance and recovery, expanding our understanding of HSP20 proteins' biological functions.

RNAi-Mediated FoxO Silencing Inhibits Reproduction in Locusta migratoria.

FoxO is a downstream target gene of cellular nutrient and growth factors, oxidative stress responses, and insulin signaling pathways. It play a crucial role in insect growth, development, and reproduction. Locusta migratoria is a significant agricultural pest; therefore, the identification of novel control targets for its management is of significant importance. After injecting dsRNA to interfere with FoxO expression, we observed changes in the reproduction-related gene expression and ovary development through RT-qPCR and morphological observation. Simultaneously, the trehalose and glycogen contents were measured following RNAi. The results demonstrate that interference with FoxO significantly downregulates key genes in the Hippo pathway and Notch gene expression. In terms of carbohydrate metabolism, the trehalose content decreases significantly while the glycogen content increases markedly after FoxO silencing. Additionally, FoxO silencing considerably inhibits reproductive-related gene expression, resulting in delayed ovarian development. These findings indicate that FoxO regulates L. migratoria reproduction through the Hippo signaling pathway: when impaired, the reproductive capacity function declines. In addition, FoxO-mediated energy mobilization is involved in the regulation of egg production. These results indicate that the RNAi of FoxO may be a useful control strategy against L. migratoria.

Identification of reproduction-related genes in the hypothalamus of sheep (Ovis aries) using the nanopore full-length transcriptome sequencing technology

The hypothalamus is the coordination center of the sheep (Ovis aries) endocrine system and plays an important role in the reproductive processes of sheep. However, the specific mechanism by which the hypothalamus affects sheep reproductive performance remains unclear. In this study, the hypothalamus tissues of high-reproduction small-tailed Han sheep and low-reproduction Wadi sheep were collected, and full-length transcriptome sequencing by Oxford Nanopore Technologies (ONT) was performed to explore the key functional genes associated with sheep fecundity. The differentially expressed genes (DEGs) were screened and enriched using DESeq2 software through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Approximately 41.75 million clean reads were obtained from the hypothalamus tissues of high- and low-reproduction sheep, after quality control, 32,194,872 high-quality full-length sequences and 2,114 DEGs were obtained, including 1,247 upregulated genes and 867 downregulated genes (P adjust < 0.05, |log2FC|>1). Some DEGs were enriched in oocyte meiosis, progesterone-mediated oocyte maturation, estrogen signaling pathway, GnRH signaling pathway and other development-related signaling pathways. The constructed protein-protein interaction (PPI) networks identified the reproduction-related genes, such as GSK3B, PPP2R1B, and PPP2CB. The results of this study will enrich and supplement the genomic information available for small-tailed Han sheep and Wadi sheep, as well as expand the understanding of the molecular mechanisms underlying the regulation of animal reproduction by the hypothalamus, and they also provided reference data for further investigations on the mechanism of high reproduction in sheep.

Transcriptomic analysis of the gonads of Locusta migratoria (Orthoptera: Acrididae) following infection with Paranosema locustae.

Paranosema locustae is an environmentally friendly parasitic predator with promising applications in locust control. In this study, transcriptome sequencing was conducted on gonadal tissues of Locusta migratoria males and females infected and uninfected with P. locustae at different developmental stages. A total of 18,635 differentially expressed genes (DEGs) were identified in female ovary tissue transcriptomes, with the highest number of DEGs observed at 1 day post-eclosion (7141). In male testis tissue transcriptomes, a total of 32,954 DEGs were identified, with the highest number observed at 9 days post-eclosion (11,245). Venn analysis revealed 25 common DEGs among female groups and 205 common DEGs among male groups. Gene ontology and Kyoto Encyclopaedia of Genes and Genome analyses indicated that DEGs were mainly enriched in basic metabolism such as amino acid metabolism, carbohydrate metabolism, lipid metabolism, and immune response processes. Protein-protein interaction analysis results indicated that L. migratoria regulates the expression of immune- and reproductive-related genes to meet the body's demands in different developmental stages after P. locustae infection. Immune- and reproductive-related genes in L. migratoria gonadal tissue were screened based on database annotation information and relevant literature. Genes such as Tsf, Hex1, Apolp-III, Serpin, Defense, Hsp70, Hsp90, JHBP, JHE, JHEH1, JHAMT, and VgR play important roles in the balance between immune response and reproduction in gonadal tissues. For transcriptome validation, Tsf, Hex1, and ApoLp-III were selected and verified by quantitative real-time polymerase chain reaction (qRT-PCR). Correlation analysis revealed that the qRT-PCR expression patterns were consistent with the RNA-Seq results. These findings contribute to further understanding the interaction mechanisms between locusts and P. locustae.

Effects of 5α-reductase inhibition by dutasteride on reproductive gene expression and hormonal responses in zebrafish embryos

Steroid 5α-reductase (SRD5A) is a crucial enzyme involved in steroid metabolism, primarily converting testosterone to dihydrotestosterone (DHT). Dutasteride, an inhibitor of SRD5A types 1 and 2, is widely used for treating benign prostatic hyperplasia. An adverse outcome pathway (AOP) has been documented wherein SRD5A inhibition decreases DHT synthesis, leading to reduced levels of 17β-estradiol (E2) and vitellogenin (VTG), subsequently impairing fecundity in fish (AOP 289). However, the molecular and cellular mechanisms underlying these effects remain poorly understood. In this study, we assessed the impact of SRD5A inhibition on zebrafish embryos (Danio rerio). Exposure to dutasteride resulted in decreased DHT, E2, and VTG levels, showing a positive correlation. Dutasteride also downregulated the expression of reproduction-related genes (srd5a2, cyp19a1, esr1, esr2a, esr2b, and vtg), with interrelated reductions observed across these levels. Docking studies suggested that dutasteride's effects may operate independently of androgen receptor (AR) and estrogen receptor (ER) interactions. Furthermore, co-exposure of dutasteride (0.5 or 2 μM) with 0.5 μM DHT revealed gene expression levels comparable to the control group. These findings underscore DHT's pivotal role in modulating estrogenic function and the interplay between estrogenic and androgenic responses in vertebrates. Our proposed AOP model offers insights into mechanistic gaps, thereby enhancing current understanding and bridging knowledge disparities.

Sublethal and transgenerational effects of tetraniliprole on the tomato pinworm Phthorimaea (=Tuta) absoluta (Lepidoptera: Gelechiidae)

Invasive pest species of economic importance often require intensive pesticide use, leading to recurrent problems of pesticide resistance. Such is the case with the tomato pinworm, Phthorimaea (=Tuta) absoluta (Meyrick) (Lepidoptera: Gelechiidae), requiring the use of new insecticidal compounds for their management. Tetraniliprole, a novel insecticide effective against lepidopteran, coleopteran, and dipteran pests, is a potential alternative against the tomato pinworm. This study investigates the sublethal effects of tetraniliprole on the development and reproduction of the parental (F0) and progeny (F1) generations of P. absoluta while exploring the underlying mechanisms. Sublethal tetraniliprole exposure extended larval duration and reduced pupation rate, emergence rate, hatchability, and fecundity in both the F0 and F1 of P. absoluta. Additionally, the life-table parameters of the F1 generation were significantly altered, with decreases in net reproductive rate (R0) and increases in the mean generation time (T), leading to decreases in the intrinsic rate of population growth (r). The relative fitness of F1 insects exposed to tetraniloprole was reduced compared to unexposed insects (0.63 and 0.49, respectively). Furthermore, the mRNA expression levels of reproduction-related genes such as TaVg and TaVgR were down-regulated in the tetraniliprole-exposed insects. Finally, insect exposure to tetraniloprole increases the activity of the antioxidant enzymes such as glutathione S-transferase (GSTs), catalase (CAT), and superoxide dismutase (SOD). Taken together, these findings suggest that sublethal concentrations of tetraniloprole adversely affect both the development and reproduction of P. absoluta, providing a foundation for optimizing pest control strategies.

Short photoperiod inhibited gonadal growth and elevated hypothalamic Dio3 expression unrelated to promoter DNA methylation in young Brandt's voles.

Photoperiod, the length of daylight, has a significant impact on the physiological characteristics of seasonal breeding animals, including their somatic and gonadal development. In rodents, expression of deiodinase type II (Dio2) and III (Dio3) in the hypothalamus is crucial for responding to photoperiodic signals. However, research on the photoperiodism of hypothalamic gene expression and the corresponding regulatory mechanism in Brandt's voles living in the Mongolian steppes is limited. In this study, we gradually changed day length patterns to simulate spring (increasing long photoperiod, ILP) and autumn (decreasing short photoperiod, DSP). We compared the somatic and gonadal development of voles born under ILP and DSP and the expression patterns of five reproduction-related genes in the hypothalamus of young voles. The results showed that DSP significantly inhibited somatic and gonadal development in both female and male offspring. Compared with ILP, Dio3 expression was significantly upregulated in the hypothalamus under DSP conditions and remained elevated until postnatal week 8 in both males and females. However, there was no significant difference in the methylation levels of the proximal promoter region of Dio3 between ILP and DSP, suggesting that methylation in the proximal promoter region may not be involved in regulating the expression of Dio3. These findings suggest that hypothalamic expression of Dio3 plays a key role in the photoperiodic regulation of gonadal activity in Brandt's voles. However, it appears that CpGs methylation in the promoter region is not the main mechanism regulating Dio3 expression.

Ethanol-related transcriptomic changes in mouse testes

BackgroundAlcohol consumption is widely known to have detrimental effects on various organs and tissues. The effects of ethanol on male reproduction have been studied at the physiological and cellular levels, but no systematic study has examined the effects of ethanol on male reproduction-related gene expression.ResultsWe employed a model of chronic ethanol administration using the Lieber-DeCarli diet. Ethanol-fed mice showed normal testicular and epididymal integrity, and sperm morphology, but decreased sperm count. Total RNA sequencing analysis of testes from ethanol-fed mice showed that a small fraction (∼ 2%) of testicular genes were differentially expressed in ethanol-fed mice and that, of these genes, 28% were cell-type specific in the testis. Various in silico analyses were performed, and gene set enrichment analysis revealed that sperm tail structure-related genes, including forkhead box J1 (Foxj1), were down-regulated in testes of ethanol-fed mice. Consistent with this result, ethanol-fed mice exhibited decreased sperm motility.ConclusionThis study provides the first comprehensive transcriptomic profiling of ethanol-induced changes in the mouse testis, and suggests gene expression profile changes as a potential mechanism underlying ethanol-mediated reproductive dysfunction, such as impaired sperm motility.

Effect of dietary daidzein supplementation on reproductive performance, egg quality and bone mineralization in laying hens at first-cycle of production via reproductive-growth axis

Daidzein (Da), an isoflavone, resembles natural oestrogen in structure and activity. We investigated the effects of dietary Da on the reproductive performance, egg quality, and bone mineralisation of hens in the pre-peak laying period. A total of 432 laying hens (110 days) were randomly allocated to control (CON) or Da-supplemented diet (10, 25, and 50 mg/kg). Each treatment had six replicates of 18 birds/replicate, and the feeding trial lasted 8 weeks. Supplementation of dietary Da significantly improved laying rate, egg weight, egg mass, and feed-to-egg ratio (p < 0.05). Likewise, dietary Da significantly improved albumen quality (Haugh unit, thick albumen fraction, and albumen proportion) and eggshell quality (eggshell; strength, eggshell thickness, gloss, and colour) (p < 0.05). Dietary Da exerted a notable significant increase (p < 0.05) on magnum weight, follicle numbers, serum levels of growth hormones, thyroid hormones (T3 and T4), reproductive hormone (oestrogen, follicle-stimulating hormone, luteinizing hormone), and mRNA expression of related genes (ESR1, FSHR1, PRL1, GNHR1). Also, Da significantly increased serum levels of superoxide dismutase, catalase, glutathione and decreased malondialdehyde (p < 0.05). Furthermore, the Da groups showed enhanced tibia strength, length, phosphorus, and bone mineral content (p < 0.05). In summary, dietary Da enhanced early onset of lay and improved albumen, eggshell, and bone quality in laying hens during the pre-peak period. Positive outcomes may be due to the efficient metabolism of Da and the safety level of inclusion. The enhancement of reproductive hormones, related genes, and antioxidant enzymes may explain daidzein’s effects on laying hens. Highlights Daidzein improved egg production significantly. Albumen, eggshell and tibia quality were enhanced. Optimal inclusion level at 25 or 50 mg/kg was safe.

Honey bee (Apis cerana) queen rearing methods influence queen morphological characteristics and reproductive related gene expression

The quality of the queen is crucial for the survival and growth of honey bee colonies. There have been studies related to raising queens with excellent performance since the invention of artificial queen rearing technologies. However, relatively few studies have been undertaken that evaluate the relationship between queen quality and queen morphology and the expression level of reproduction-related genes using different-aged brood in artificial queen rearing practices of Eastern honey bees (Apis cerana). Therefore, we transferred eggs, 1-day-old larvae, 2-day-old larvae, and 3-day-old larvae to queen cells to rear queens until the queen emerged. We measured 12 indicators (the acceptance rate, birth weight, length, caliber and maximum diameter of queen cells, thorax length, width and weight, head width, wing length and width, and number of ovarian tubes). Moreover, the relative expression levels of Hexamerin, Vitellogenin, and Transferrin were measured using fat bodies and ovaries dissected from the newly emerged virgin queens. The results showed that queens reared from eggs exhibited the best morphological indexes and occupied the most abundant reproductive related gene expression level. Parameter values for queen from 1-day-old larvae were significantly higher than those for queens from 2-day-old larvae and 3-day-old larvae, and there was no significant difference between values for queens from 2-day-old larvae and 3-day-old larvae in most data, except for the relative gene expression. In conclusion, as the age of the brood increased, the quality of the queen bees declined. Rearing queens from fertilized eggs are far more likely to yield a better outcome for queen performance and colony function. This study provides data support for raising high-quality queens of Apis cerana, which would be benefit for the protection and better utilization of our native honey bee species.

Pituitary transcriptome analysis of mandarin fish (Siniperca chuatsi) reveals dietary 17α-methyltestosterone disturbs hypothalamic-pituitary-gonadal axis by FSH signaling pathway

17α-methyltestosterone (MT), as a synthetic androgen, has been widely used in medicine and aquaculture industry. However, the related molecular regulating mechanism of MT effects on hypothalamic-pituitary-gonadal axis has not been well addressed. This study first evaluated the effects of MT treatment on pituitary of mandarin fish (Siniperca chuatsi). Transcriptome analysis revealed a lot of differentially expressed genes were found in pituitary after MT treatment in early stage (10 and 20 dat), with a relatively few genes found in late stage (30 and 40 dat). Among them, several reproduction related genes were significantly upregulated after MT treatment, while only the expression of follicle-stimulating hormone beta submit (fshb) was significantly inhibited in all stages. Moreover, in vitro experiment also revealed MT significantly inhibited the expression of fshb and promoted the expression of androgen receptors in pituitary. However, dual-luciferase assay revealed that MT activated the promotor activity of fshb via androgen receptors. Finally, we also demonstrated FSH could directly activate the promotor of cyp19a1a by several ways. In all, we first demonstrated exogenous MT could inhibit the expression of fshb in pituitary and further decrease the production of estrogen in gonad by FSH signaling pathway in mandarin fish.

Phenytoin causes behavioral abnormalities and suppresses kisspeptin expression, reducing reproductive performance in Japanese medaka

Phenytoin, an antiepileptic drug, induces neurotoxicity and abnormal embryonic development and reduces spontaneous locomotor activity in fish. However, its effects on other endpoints remain unclear. Therefore, we investigated the effects of phenytoin on the swimming behavior and reproductive ability of Japanese medaka. Abnormalities in swimming behavior, such as imbalance, rotation, rollover, and vertical swimming, were observed. However, when phenytoin exposure was discontinued, the behavioral abnormality rates decreased. Phenytoin exposure also significantly reduced reproductive ability. By investigating reproduction-related gene expression of gnrh1, gnrh2, fshb, and lhb remained unchanged in males and females. In contrast, kiss1 expression was significantly suppressed due to phenytoin exposure in males and females. kiss2 expression was also significantly suppressed in females but not in males. We filmed videos to examine phenytoin exposure effects on sexual behavior. Females showed no interest in the male's courtship. As the kisspeptin 1 system controls sexual behavior in Japanese medaka, phenytoin exposure may have decreased kiss1 expression, which decreased female reproductive motivation; hence, they did not spawn eggs. This is the first study to show that phenytoin exposure induces behavioral abnormalities, and suppresses kiss1 expression and reproductive performance in Japanese medaka.

The Role of Placental DNA Methylation at Reproduction-Related Genes in Associations between Prenatal Bisphenol Analogues Exposure and the Digit Ratio in Children at Age 4: A Birth Cohort Study.

Placental DNA methylation (DNAm) may be a potential mechanism underlying the effects of prenatal bisphenol analogues (BPs) exposure on reproductive health. Based on the Shanghai-Minhang Birth Cohort Study (S-MBCS), this study investigated associations of placental DNAm at reproduction-related genes with prenatal BPs exposure and children's digit ratios at age 4 using multiple linear regression models, and mediation analysis was further used to examine the mediating role of placental DNAm in the associations between prenatal BPs exposure and digit ratios among 345 mother-child pairs. Prenatal exposure to bisphenol A (BPA) was associated with hypermethylation at Protocadherin 8 (PCDH8), RBMX Like 2 (RBMXL2), and Sperm Acrosome Associated 1 (SPACA1), while bisphenol F (BPF) exposure was associated with higher methylation levels of Fibroblast Growth Factor 13 (FGF13). Consistent patterns were found in associations between higher DNAm at the 4 genes and increased digit ratios. Further mediation analysis showed that about 15% of the effect of BPF exposure on increased digit ratios was mediated by placental FGF13 methylation. In conclusion, the altered placental DNAm status might be a mediator underlying the feminizing effect of prenatal BPs exposure.

First insight of the intergenerational effects of tri-n-butyl phosphate and polystyrene microplastics to Daphnia magna

As an emerging organic pollutant, tributyl phosphate (TnBP) can be easily adsorbed by microplastics, resulting in compound toxic effects. In the present work, the effects of polystyrene microplastics (PS-MPs) and TnBP on the survival, growth, reproduction and oxidative stress of Daphnia magna (D. magna) have been evaluated through multigenerational test. Compared with the alone exposure groups, the somatic growth rate and the expression values of growth related genes rpa1, mre11, rnha, and rfc3_5 in the F1 generation of the combined exposure groups were significantly lower (p < 0.05), indicating synergistic effect of PS-MPs and TnBP on the growth toxicity and transgenerational effects. In addition, compared with the PS-MPs groups, significantly lower average number of offspring and expression values of reproduction related genes ccnb, mcm2, sgrap, and ptch1 were observed in the combined exposure group and TnBP group (p < 0.05), indicating TnBP might be the major factor causing reproductive toxicity to D. magna. Although PS-MPs and TnBP alone or in combination also had toxic impacts on the growth, survival and reproduction of D. magna in generations F0 and F2, the effects were less than F1 generation. Regarding oxidative stress, the activity of SOD, CAT and GSH-Px and MDA content in the generations F0 and F1 of combined exposure groups were higher than the TnBP group but lower than the PS-MPs groups, suggesting that PS-MPs might be the dominant cause of the oxidative damage in D. magna and the presence of TnBP would alleviate oxidative stress by reducing the bioaccumulation of PS-MPs. The present work will provide a theoretical basis for further understanding of the toxic effects and ecological risks of combined TnBP and microplastic pollution on aquatic organisms.