Search Results (322)

The Anti-Müllerian hormone (AMH) is widely recognized for promoting Müllerian duct regression in higher vertebrates and regulating key reproductive functions like steroidogenesis, folliculogenesis, and Leydig cell development. In teleost fish, which lack Müllerian ducts, Amh primarily influences male reproductive functions, including sex determination, testis differentiation, and germ cell proliferation. In adult fish, Amh supports gonad development and spermatogenesis, but its role in teleost gonadal physiology remains largely underexplored. This study reveals a novel steroidogenic function in the European sea bass (Dicentrarchus labrax) using in vitro testis culture, in vivo plasmid injection, and cell-based transactivation assays. The Amh-induced significant increase in androgen levels was also confirmed in Japanese medaka (Oryzias latipes) treated with recombinant sea bass Amh. Beyond activating the canonical Smad pathway, Amh also triggered the cAMP/PKA signalling pathway via its cognate type II receptor, Amhr2. Inhibitors of these pathways independently and synergistically counteracted Amh-induced CRE-Luc activity, indicating pathway crosstalk. Moreover, inhibition of the cAMP pathway suppressed Amh-induced androgen production in testis cultures, emphasizing the crucial role of protein kinase A in mediating Amh steroidogenic action. These findings uncover a novel steroidogenic function of Amh in teleosts and highlight its broader role in male reproductive physiology. Full article

The white-spotted jellyfish, Phyllorhiza punctata, is an invasive species with significant ecological and economic relevance spreading across various regions. While its ecological impact is well-documented, its molecular and biochemical characteristics remain poorly understood. In this study, we integrate proteomic data generated by LC-MS/MS with publicly available transcriptomic information to characterize P. punctata, analyzing differential protein expression across three distinct tissues: oral arms, mantle, and gonads. A total of 2764 proteins and 25,045 peptides were identified, including several venom components such as jellyfish toxins (JFTs) and phospholipase A2 (PLA2), which were further investigated and compared to toxins from other species. Enrichment analyses revealed clear tissue-specific functions. Additionally, deep learning and machine learning tools identified 274 promising AMP candidates, including the α-helical, β-sheet, and αβ-motif peptides. This dataset provides new insights into the protein composition of P. punctata and highlights strong AMP candidates for further characterization, underscoring the biotechnological potential of underexplored cnidarian species. Full article

Appendage autotomy frequently occurs during the cultivation of Exopalaemon carinicauda, which severely impacts its survival and economic benefits. To investigate the molecular mechanism underlying appendage regeneration in E. carinicauda, this study presents a comparative transcriptome analysis on samples from different stages of appendage regeneration in individuals of the same family of E. carinicauda. A total of 6460 differentially expressed genes (DEGs) were identified between the samples collected at 0 h post-autotomy (D0) and those collected at 18 h post-autotomy (D18h). Additionally, 7740 DEGs were identified between D0 and 14 d post-autotomy (D14d), with 3382 DEGs identified between D18h and D14d. Among them, differentially expressed genes such as EcR, RXR, BMP1, and Smad4 are related to muscle growth or molting and may be involved in the regeneration process. qRT-PCR results revealed that EcBMPR2 was expressed at relatively high levels in the gonad and ventral nerve cord tissues and that the highest level of expression was detected in the regenerative basal tissue at 24 h post-autotomy. In situ hybridization results indicated strong signals of this gene in the cells at the wound site at 72 h post-autotomy. Following knockdown of EcBMPR2, the expression levels of both EcBMPR1B and EcSmad1 were significantly downregulated, and long-term interference with the EcBMPR2 gene resulted in a significantly slower appendage regeneration process compared to the control group. When the downstream transcription factor EcSmad1 was knocked down, the two receptor genes EcBMPR2 and EcBMPR1B were downregulated, whereas EcBMP7 was upregulated. After inhibiting the BMP signaling pathway, the degree of cell aggregation at the autotomy site in the experimental group was significantly lower than that in the control group, the wound healing rate was delayed, and the blastema regeneration time was prolonged from 5 d to 7 d. Collectively, these results indicate that the BMP signaling pathway plays a critical role in the early stages of appendage regeneration in E. carinicauda. This study provides important theoretical insights for understanding limb regeneration in crustaceans. Full article

Megalobrama terminalis is a significant aquatic fish in South China, renowned for its tasty meat. Nonetheless, related studies are deficient concerning the gonadal development of M. terminalis. This paper presents the first comparative transcriptome analysis of the gonads of female and male M. terminalis. A total of 84,886 unigenes were assembled, with 42,322 effectively annotated to the Nr, SwissProt, KEGG, KOG, and GO databases. Furthermore, comparative transcriptomic analysis of M. terminalis was conducted to examine its gonadal development. A total of 14,972 differentially expressed genes (DEGs) were discovered. In the testis, the expression of 11,928 unigenes was significantly upregulated, while 3044 were significantly downregulated. Numerous DEGs associated with steroidogenesis, gonadal differentiation and development, and gametogenesis in teleost fish were identified. The results provide empirical support for further study of genes and pathways associated with sex determination and gonadal differentiation in teleost fish. Full article

This study elucidates the role of the steroidogenic acute regulatory protein (StAR) in sex steroid hormone dynamics and the gonadal development of the commercially important marine bivalve ark shell Scapharca broughtonii. The sequence of the StAR gene was obtained and verified from the transcriptome of ark shell, then the tissue localization and expression pattern during the gonad development of the StAR gene were detected by in situ hybridization and quantitative real-time PCR, respectively. Additionally, the concentrations of three critical sex steroid hormones (progesterone, testosterone, and estradiol) were measured throughout gonadal development using enzyme-linked immunosorbent assay (ELISA). The results showed that the length of the coding region of StAR was 1446 bp, encoding 481 amino acids. The results of qRT-PCR showed that the expression of the StAR gene varied with gonadal development, increased from the early active stage to the development stage, and decreased from the mature stage to the spent stage. Notably, the expression level in ovaries was higher than that in testes, suggesting the potential involvement of StAR in sex differentiation and gonadal development. Additionally, the results indicated that progesterone, testosterone, and estradiol accounted for 80%, 10%, and 10% of the total hormone content in the gonads, respectively. Correlation analysis revealed a highly significant strong positive correlation between progesterone/estradiol levels and StAR gene expression, demonstrating that StAR serves as a key regulator in sex steroid hormone biosynthesis. These findings provide crucial molecular evidence for StAR-mediated steroidogenesis in bivalve reproduction, offering fundamental insights into invertebrate endocrinology. Full article

As a commercially valuable aquaculture species, rainbow trout (Oncorhynchus mykiss) urgently require solutions to growth inhibition associated with reproductive development. To elucidate the function of the cell cycle regulator Cyclin E genes (CCNE1 and CCNE2) in this process, we cloned the genes and analyzed their relative expression across various tissues and gonadal developmental stages. Using RNA interference (RNAi) and overexpression in RTG2 cells, we examined the effects of CCNE on cell viability, proliferation, and meiotic gene expression. Results showed that the open reading frame lengths of CCNE1 and CCNE2 were 1230 bp and 1188 bp, encoding 408 and 395 amino acids, respectively. Both proteins contain two conserved cyclin boxes, exhibit high structural similarity, and are phylogenetically most closely related to Oncorhynchus tshawytscha and Oncorhynchus kisutch. Expression and localization analyses revealed that CCNE1 was highly expressed in the ovary, while CCNE2 was highly expressed in the testis. Both proteins were expressed during fertilized egg development and key gonadal stages (at 13, 21, and 35 months post-fertilization). CCNE expression positively correlated with RTG2 cell viability and proliferation, with immunofluorescence confirming that CCNE is localized in the nucleus. Knockdown or overexpression of CCNE induced the differential expression of reproductive-related genes and key meiotic regulators. These findings suggest that CCNE1 and CCNE2 balance meiosis and gamete development through specific regulatory mechanisms, and their dysregulation may be a key factor underlying meiosis inhibition and reproductive development abnormalities. Full article

Urogenital cannulation is a traditional method used in aquaculture to achieve sexual differentiation, but it is considered invasive. Ultrasonography is a valuable non-invasive tool for determining sex and gonadal development in fish species like mullet (Mugil liza) and Brazilian sardine (Sardinella brasiliensis) that lack sexual dimorphism. The methodology involves emitting high-frequency sound waves (20 MHz to 20,000 MHz) above the human hearing range. These waves interact with the tissues of the body, producing echoes that are detected by a transducer. The echoes are then processed by computer graphics to generate detailed images of the internal structures of the organism. This allows for the determination of the sex of fish based on the sonographic features of the tissues. For instance, in male fish, hypoechogenic structures reflect fewer sound waves, leading to darker images. Conversely, in female fish, hyperechogenic tissues reflect more sound waves, resulting in lighter images. It is possible to classify the gonadal maturation stage based on differences in image texture. This non-invasive method eliminates the need for specimen dissection. It is especially valuable when the goal is to preserve the spawners’ life and integrity. This review emphasizes the application of this technology in aquaculture, specifically targeting fish from the Clupeidae and Mugilidae families. Full article

The creation of transgenic chickens holds significant promise for the agricultural and biotechnological sectors, offering potential improvements in disease resistance and production efficiency. The preferred method for generating gene-edited chickens involves the genetic manipulation of primordial germ cells (PGCs), making the identification and isolation of these cells a growing focus of research. PGCs are the precursors to sperm and oocytes, responsible for transmitting genetic material to the next generation. In humans, PGCs are characterized by their large size, round nuclei, and refractive lipids in the cytoplasm, and can be identified using periodic acid–Schiff (PAS) staining and the surface marker stage-specific embryonic antigen 1 (SSEA1). Similarly, chicken PGCs express SSEA1, but their most specific marker is the chicken vasa homologue (CVH), the avian equivalent of the RNA-binding factor gene vasa. However, SSEA1, along with other known surface markers, does not bind to all PGCs or lacks specificity, while CVH, although highly specific to PGCs, is intracellular and unsuitable for isolating viable cells. This study aims to develop an antibody targeting a PGC surface marker with the same specificity as CVH. Despite the importance of identifying surface markers for PGC characterization, to date, such reagents are limited. To address this, whole chicken PGCs were injected into mice, leading to the generation of a panel of monoclonal antibodies. One antibody was found to bind cultured chicken PGCs and showed reduced expression upon differentiation with retinoic acid, indicating its specificity to PGCs. Immunoprecipitation followed by mass spectrometry identified the antigen as myosin heavy chain-like (MYH9) protein. The antibody, αMYH9, was further characterized and shown to bind circulating PGCs and embryonic gonadal PGCs (Hamburger Hamilton (H-H) stage 30, embryonic day 6.5–7). Whilst our primary aim was to determine the binding to PGCs, further investigation is required to determine potential binding to somatic cells. In conclusion, this study provides the characterization of a surface marker for chicken PGCs, with significant implications for advancements in avian genetic preservation, agriculture, and biotechnology. Full article

This study aims to clarify the dose–response relationship between dietary β-carotene levels and gonadal pigment deposition and regulation mechanisms related to the carotenoid synthesis of Strongylocentrotus intermedius based on a 60-day feeding trial and subsequent transcriptome analysis. Adult sea urchins (initial weight: 9.33 ± 0.21 g) of three cages were given one of the dry feeds with different doses of β-carotene (0 mg/kg, 150 mg/kg, 300 mg/kg) or fresh kelp (Saccharina japonica). The results indicated that the weight gain rate (WGR) of sea urchins increased with the addition of β-carotene, with that of the C300 group being markedly higher than that of the C0 group. The addition of β-carotene significantly improved the redness (a*) and yellowness (b*) values of the gonads, with sea urchins in the C300 group exhibiting closest gonad coloration to those in the kelp-fed group. Meanwhile, β-carotene and echinenone in the gonads of the C300 group showed the highest contents, reaching 1.96 μg/kg and 11.97 μg/kg, respectively. Several differential genes, enriched in the pathways of steroid biosynthesis, oxidative phosphorylation, and ubiquitination, were screened based on transcriptome analysis. Real-time PCR further demonstrated that β-carotene significantly upregulated the expression of cholesterol 25-hydroxylase (CH25H), NADH dehydrogenase subunit 1 (ND1), NADH dehydrogenase subunit 2 (ND2), and NADH dehydrogenase subunit 4 (ND4) while it downregulated the expression of 24-dehydrocholesterol reductase (DHCR24). These results showed that 300 mg/kg β-carotene significantly increased the WGR, redness, and yellowness values, as well as the contents of β-carotene and echinenone in the gonads of S. intermedius. On the one hand, dietary β-carotene increased NADH enzyme activity, which participates in echinenone synthesis by donating electrons for the transformation of β-carotene to echinenone synthesis. On the other hand, the addition of β-carotene inhibited cholesterol synthesis by increasing the expression of CH25H and decreasing the expression of DHCR24, which could in turn increase the fluidity and permeability of the cell membranes and the transport efficiency of β-carotene and echinenone from the digestive tract to the gonads. These results provided fundamental insights into the production of sea urchin gonads with market-favored colors. Full article

The germline stem cells (GSCs) in the male gonad of Drosophila can increase their division frequency in response to a demand for more sperm caused by repeated mating. However, the molecules and mechanisms regulating and mediating this response have yet to be fully explored. Here, we present the results of a transcriptome analysis comparing expression from the testis tips from non-mated and mated males. An overlapping set of 18 differentially expressed genes (DEGs) from two independent wild-type (wt) strains revealed that the majority of the DEGs encode secreted proteins, which suggests roles for them in cell–cell interactions. Consistent with a role for secretion in regulating GSC divisions, knocking down Signal Recognition Particle (SRP) components within the germline cells using RNA Interference (RNAi), prevented the increase in GSC division frequency in response to mating. The major class of DEGs encodes polypeptides below the size of 250 amino acids, also known as small proteins. Upon reducing germline expression of small proteins, males no longer increased GSC division frequency after repeated mating. We hypothesize that mating induces cellular interactions via small proteins to ensure continued GSC divisions for the production of sperm. Full article

The Pacific white shrimp, Litopenaeus vannamei (L. vannamei), is an important aquaculture species, yet the molecular mechanisms underlying its sex differentiation and gonadal development remain poorly understood. A deeper understanding of these processes is critical for advancing broodstock quality and enabling unisex breeding strategies. While previous studies have focused on gene expression differences between females and males, structural differences in transcriptomic regulation between sexes have been largely overlooked. Here, we present a comprehensive full-length transcriptome analysis of L. vannamei testis and ovary, identifying 830 and 690 novel genes, respectively, and over 6000 new isoforms. Notably, we discovered extensive alternative splicing (AS) events, with the cartilage oligomeric matrix protein-like gene exhibiting over 300 AS isoforms in the ovary compared to only 2 in the testis, suggesting a potential role in ovarian development. Furthermore, sex-determining genes such as Fem-1a, Fem-1c, and Sxl were found to produce AS isoforms exclusively in ovarian tissue. We also identified three germ cell development-associated genes—MAD2-like, RAD51-like, and Su(dx)-like—that undergo distinct AS events in gonadal tissues, leading to sex-specific structural domain alterations. These findings highlight the complexity of AS-mediated post-transcriptional regulation in L. vannamei and provide novel insights into the molecular mechanisms governing sex differentiation and gonadal development. Full article

Precocious puberty, defined as the onset of secondary sexual characteristics before age 8 in girls, presents a diagnostic challenge in distinguishing between normal variants and pathological conditions requiring intervention. Central precocious puberty (CPP) results from early activation of the hypothalamic–pituitary–gonadal axis, whereas peripheral precocious puberty (PPP) arises from excess sex steroid production independent of gonadotropins. Benign variants, including premature thelarche and premature adrenarche, require careful differentiation to prevent unnecessary treatment. This review explores the physiological mechanisms governing puberty, the epidemiological trends influencing its early onset, and the genetic and environmental factors contributing to its variability in female children. A structured diagnostic approach incorporating clinical evaluation, hormone assessments, imaging studies, and genetic insights is discussed. Management strategies vary depending on the etiology, with gonadotropin-releasing hormone analogs recommended for CPP and targeted therapies for PPP. In contrast, benign variants often necessitate observation and periodic follow-up. Given the increasing prevalence of early puberty, further research is essential to refine diagnostic thresholds and optimize treatment protocols. Early and accurate identification of precocious puberty ensures appropriate intervention, mitigating potential risks associated with early maturation, including compromised adult height and psychosocial challenges. Full article

Chlorfenapyr is a widely used insecticide known to harm non-target insects, but its effects on reproductive development in the silkworm (Bombyx mori L.) remain incompletely understood. In this study, we investigated the histopathological and transcriptional changes in the gonads (ovaries and testes) of newly molted fifth-instar silkworm larvae exposed to chlorfenapyr. Histopathological analysis revealed delayed gonadal development, a reduction in oogonia and oocytes in the ovaries, and decreased numbers of spermatocytes in the testes. Transcriptome analysis identified significant differentially expressed genes (DEGs), mainly enriched in pathways such as “Drug metabolism—cytochrome P450”, “Insect hormone biosynthesis”, and “Ribosome”. Key up-regulated genes included members of the cytochrome P450 family (CYP6B5, CYP9f2, CYP6B6), glutathione S-transferases (GSTT1, GST1), and juvenile hormone-related enzymes (JHAMT, JHEH), indicating active detoxification and hormonal regulation responses. Several transcription factor families, particularly C2H2, HB-other, and TRAF, exhibited altered expression, suggesting roles in stress adaptation. Protein–protein interaction (PPI) network analysis identified hub genes such as EcR, Kr-h1, and various ribosomal proteins, highlighting their potential involvement in reproductive development. Quantitative PCR (qPCR) validated the transcriptomic data, confirming the reliability of the results. Overall, these findings enhance our understanding of chlorfenapyr’s impact on silkworm reproductive development and the underlying molecular mechanisms, providing valuable insights for sustainable pest management and ecological risk assessment of insecticides. Full article

Background: While the mechanism of asymmetric gonadal development is generally understood, the mechanism of asymmetric oviduct development remains unclear. Methods: Right and left oviducts were collected from chick embryos at three developmental stages (Embryonic day 7.5, E9.5, and E11.5) for RNA-seq analysis (RNA-seq). Whole-genome resequencing (WGRS) was performed on hens with bilateral reproductive systems (a rare natural occurrence) and unilateral controls. These data were co-analyzed with public RNA-seq data of female embryonic gonads at different developmental stages (E4.5, E5.5, and E6.5) to screen for candidate genes affecting oviduct degeneration/development. Results: RNA-seq analyses showed that a total of 27, 10, and 38 DEGs were identified between the left and right oviducts at E7.5, E9.5, and E11.5, respectively. WGRS analyses revealed 1045 differentially mutated genes (DMGs) between bilateral (D) and unilateral (S) groups. Preliminary validation highlighted BMP7, PAK3, SLC6A11, PITX2, and SMC1B as candidate genes influencing oviduct asymmetry. Conclusions: This study provides insights into the genetic basis of asymmetric oviduct development and lays the groundwork for breeding hens with bilateral reproductive systems. Full article

Nr5a2 (nuclear receptor subfamily 5, group a, member 2) is involved in gonad development and sex hormone synthesis. In this study, the full length of Nr5a2f and Nr5a2m were obtained by Nr5a2 variable splicing from Andrias davidianus, and the tissue distribution was detected. We identified Nr5a2f of 2455 bp and Nr5a2m of 2150 bp length, encoding 479 and 325 amino, respectively. We first characterized Nr5a2f and Nr5a2m gene expression in developing gonads. Results showed that Nr5a2f had significantly high expression in the ovary and little expression in other tissues, during the sex differentiation and sex reversal, Nr5a2f expression was gradually decreased in the ovary and the expression in the testis was significantly lower than in the ovary from 1 year to 6 year old. Significantly high expression was observed in the ovary and reversal ovary, while low expression was in the testis and reversal testis. While Nr5a2m expression exhibited the opposite profile, high expression was observed in the brain and testis. During sex differentiation and sex reversal, high expression was shown in the testis and low expression in the ovary from one year to six years old and significantly higher expression emerged in testis and reversal testis than in ovary and reversal ovary. In situ hybridization, results showed that Nr5a2f began to express in female undifferentiated gonads and the expression level increased from 48 dpf to 91, while Nr5a2m was expressed in male undifferentiated gonads. Three RNA interference sites were designed and we detected that site 293 exhibited a significant inhibitory effect in ovary cells. After Nr5a2f expression was inhibited by site 293, we observed that female-based gene Nr5a2f, foxl2 and cyp19 expression were decreased, while the male-based gene dmrt1 and cyp17 expression was increased. These results suggested that Nr5a2f and Nr5a2m exhibited different expression patterns in the process of sex differentiation, which provided a foundation for further functional characterizations. Full article