Search Results (138)

The Transforming Growth Factor-β (TGF-β) superfamily comprises highly conserved cytokines that orchestrate key cellular functions, including proliferation, differentiation, and apoptosis. Within the ovary, TGF-β family members serve as pivotal regulators of folliculogenesis, exerting stage-specific actions from embryonic germ cell development to advanced follicular maturation. During fetal development, activins and SMAD-dependent signaling pathways are essential for primordial germ cell proliferation, survival, and the breakdown of germ cell cysts, enabling the establishment of the primordial follicle pool. Throughout folliculogenesis, TGF-β supports follicle activation, promotes the transition from dormant to growing follicles, stimulates granulosa cell proliferation, sustains follicular viability, and modulates steroidogenesis through theca cell regulation. Notably, anti-müllerian hormone, a TGF-β family member, plays a central role in inhibiting premature follicle recruitment and serves as a key biomarker of ovarian reserve. Dysregulation of TGF-β signaling contributes to various ovarian disorders, including polycystic ovary syndrome and premature ovarian insufficiency. A deeper understanding of these complex signaling networks is critical for identifying novel therapeutic targets and advancing clinical interventions in female reproductive pathologies. This review provides an integrated overview of the roles of the TGF-β superfamily in ovarian physiology and its contributions to disease development. Full article

Background: Germ cell tumors are benign or malignant tumors that originate from the human embryo’s primordial germ cells. This study aims to conduct a retrospective analysis of germ cell tumors followed up at our institution, including their epidemiological data, treatment, and prognosis. Patients and Methods: Ninety-three cases were included and retrospectively evaluated for socio-demographic features, clinical data, presenting symptoms, histopathological findings, localization, staging, treatment protocol, and survival analysis. Results: Patients were diagnosed between 10 days and 17 years 10 months (median 27.2 months); 37 (40.7%) were male, 54 (59.3%) female. The tumors were located in the sacrococcygeal region (33.3%), ovaries (26.8%), testes (25.8%), abdomen (7.5%), CNS (2.1%), liver, adrenal gland, anterior mediastinum, and spine. Thirty-nine lesions were benign, and 54 were malignant. Mature cystic teratomas (40.8%), endodermal sinus tumors (28.0%), mixed germ cell tumors (12.9%), immature teratomas (9.7%), germinoma (6.5%), gonadoblastoma (1.1%), and choriocarcinoma (1.1%) were the different types of histology. We observed metastases in 17 malignant cases, with the lungs being the most commonly affected (10.7%). Stages I, II, III, and IV included 16, 17, 11, and 10 cases, respectively. Survival rates for all cases were 95.8%, and for malignant tumors, they were 92.7%. For malignant cases, the event-free survival rate was 84.2%. Conclusions: The findings provide comprehensive epidemiological and clinical data on germ cell tumors, enhancing understanding of their distribution, treatment outcomes, and prognosis. The high survival rates observed highlight the effectiveness of current treatment protocols, as well as the importance of early diagnosis and appropriate management. Full article

Di(2-ethylhexyl) phthalate (DEHP) is known to adversely affect reproduction. Our previous study demonstrated that DEHP exposure during embryogenesis impaired fertility in adult female zebrafish. The objective of this study was to investigate developmental events underlying this effect. Embryos were exposed to DEHP 5 h post-fertilization (hpf), and the distribution of primordial germ cells (PGCs), along with the expression of genes involved in PGC migration, maintenance, and neuroendocrine regulation, was assessed. Molecular docking simulations were performed to evaluate whether DEHP’s main metabolite, mono(2-ethylhexyl) phthalate (MEHP), is able to bind to zebrafish estrogen receptors (Esr). Our results show that DEHP reduced the expression of cxcr4b, cxcr7b, esr1, and esr2a at 24 hpf. Using vasa:egfp transgenic embryos, we found that DEHP altered the distribution of PGCs. In addition, DEHP inhibited the expression of PGC-specific dazl. DEHP also induced the expression of lhb and cyp19a1 and reduced the expression of esr2a in 120 hpf larvae, consistent with disruption of the neuroendocrine reproductive axis. Molecular docking indicates that MEHP can bind to the ligand-binding domains of Esr1, Esr2a, and Esr2b. Collectively, the results show that DEHP disrupts both PGC distribution and early neuroendocrine signaling pathways, providing mechanistic insight into reduced fertility in adult female zebrafish following embryonic DEHP exposure. Full article

Primordial germ cells (PGCs) are the unipotent precursors of sperm and ova, responsible for transmitting hereditary information across generations. Their ability to be isolated and cultured in vitro has opened new horizons for avian biotechnology, species conservation, and fundamental developmental research. In birds, the unique migratory pattern of PGCs—originating in the epiblast and traveling via the bloodstream to the gonads—enables their collection and manipulation during embryogenesis. Long-term in vitro culture systems have been successfully established in chickens, where defined media allow for stable proliferation and genetic modification. Applications include germline chimeras, generation of transgenic lines, recombinant protein production, and cryobanking of genetic resources. However, translating these advances to other species remains challenging due to interspecies variability in signaling requirements. Recent work in geese, ducks, quails, and zebra finches underscores the need for tailored media formulations and a better understanding of molecular regulation. This review summarizes established techniques, highlights key interspecies differences, and outlines future directions for the standardization and expansion of avian PGC culture systems to support conservation and biotechnology. Full article

Wastewater treatment plants (WWTPs) play a key role in the protection of the environment and public health by reducing the levels of pollutants released into the water. Here, we evaluate the quality of water obtained from two key points of the treatment process of a municipal WWTP (León, Spain) using zebrafish (Danio rerio) embryos and larvae as sentinels. Three experimental groups were established: (1) “Control” (CTRL) maintained in embryo medium, (2) “Influent” (I) exposed to influent water before the secondary (biological) treatment (concentrations: I-100% and I-75%), and (3) “Effluent” (E) exposed to effluent water from the secondary treatment (concentrations: E-100% and E-75%). Our results confirmed that survival was subtly affected in I-100% and E-100%, as well as the hatching rate in the effluent. Larvae exposed to both experimental conditions also presented a higher rate of malformations, affecting biometry and showing reduced embryo motility, with the exception of E-75%. The I-100% condition also caused reduced heartbeat, reduced fin regeneration, and a higher number of delocalized primordial germ cells. I-100%-exposed larvae showed dysregulation of four genes (foxm1l, cenpf3b, hoxc6a, and ddit3) out of the 19 studied. Effluent dilution mitigated the observed effects, and the model proved to be an effective additional test for wastewater treatment plants. Full article

Avian genome editing has historically lagged behind mammalian research. This disparity is primarily due to a unique reproductive biology that precludes standard techniques like pronuclear injection. A pivotal breakthrough, however, came from the development of efficient in vitro culture systems for primordial germ cells (PGCs). This has established the chicken as a tractable and powerful model for genetic engineering. Our review chronicles the technological evolution this has enabled, from early untargeted methods to the precision of modern CRISPR-based systems. We then analyze the broad applications of these tools, which are now used to engineer disease resistance, enhance agricultural traits, and develop novel platforms such as surrogate hosts and oviduct bioreactors. Collectively, these advances have established PGC-based genome editing as a robust and versatile platform. Looking forward, emerging precision editors and the expansion of these techniques to other avian species are poised to drive the next wave of innovation in poultry science and biotechnology. Full article

Background/Objectives: Inactivation of the dnd gene involved in the development of primordial germ cells (PGCs) leads to the loss of gametes and halts reproductive development. Studies on sterile fish allow for the identification of genes and processes associated with GC differentiation. Methods: Atlantic salmon with GC-ablated testes were produced by temporal silencing of dnd. Gene expression was analyzed in sterile and fertile testes using 44k microarray and qPCR. Results: In sterile testes, transcripts of several GC markers were detected at low levels, suggesting the presence of cells with a GC-related expression profile that failed to initiate spermatogenesis. Expression of 260 genes was undetectable in the gonads of sterile males and females, and 61.5% of these were also inactivated during first maturation of fertile testes. This group was enriched with genes highly expressed in the brain, including those involved in endocrine and paracrine regulation, synaptic transmission, and numerous genes critical for brain development; among them, 45 genes encoding homeobox proteins. Another group of 229 genes showed increased expression in developing testes and included genes involved in neurosecretion and brain development regulation. GC-ablated testes showed increased expression of reproductive regulators such as amh and sdy and numerous immune genes, suggesting a reprogramming of GC-depleted testes. Temporal silencing of dnd indicated common developmental processes in the brains and gonads of Atlantic salmon testis that become inactive in testes at first maturation. These processes may play roles in PGC homing, the creation of a specific environment required for spermatogenesis, or facilitating communication between the gonads. Full article

Transition is an essential mechanism that drives the development of distinct cellular phenotypes and tumorigenesis. The expression of various types of testis cancer antigens (TCAs) in breast carcinomas suggests a potential transition to male germ cell features within the tumor. This study explores the cellular populations in breast cancer that express genes associated with male germ cell development. We re-analyzed published datasets to identify the germline-associated genes in breast tumors. We then experimentally validated the expression of the identified genes in 28 breast tissue tumor samples using a quantitative RT-PCR. Based on available datasets, we also performed single-cell RNA sequencing (scRNA-seq) to analyze the tumor heterogeneity and cellular clustering. A total of 455 overexpressed genes were identified that were related to fetal primordial germ cells (PGCs), particularly those in the male gonad. Our examinations showed a significant overexpression of five genes (CCNB1, CCNB2, PTTG1, RACGAP1, and UBE2C) in the tumor samples. The scRNA-seq analysis revealed 14 distinct cell clusters, characterized by different gene expression signatures and cell cycle phases. The breast tumor stromal cells were suggested as the main source of the germline-associated genes. This study provides insights into the molecular mechanisms and pathways involved in germ cell transition in breast carcinoma. Full article

Background/Objectives: The Germ Cell Theory of cancer posits that human primordial germ cells (hPGCs) are the cells of origin for malignancies. While this theory is well established for germ cell cancers, a germ cell origin for somatic cancers has been largely overlooked despite clinical observations of malignant somatic transformation (MST), wherein germ cell cancers give rise to diverse somatic cancer phenotypes, often without additional mutations. Methods: To test the Germ Cell Theory experimentally in somatic cancer, we established a virus-driven MST model linking hPGC-like cells (hPGCLCs) to Merkel cell polyomavirus (MCPyV)-positive Merkel cell carcinoma (MCC), a highly aggressive somatic cancer with a germ cell cancer-like, low-mutation epigenetic profile. The MCPyV genome was transduced into human induced pluripotent stem cells (hiPSCs) or hPGC-like cells by lentiviral transfection, followed by xenotransplantation. Results: Virus-positive MCC (VP-MCC)-like tumors were consistently induced without additional oncogenic mutations. These tumors recapitulated VP-MCC’s high-grade neuroendocrine carcinoma histology and molecular profiles. DNA methylation analysis revealed near-complete global hypomethylation in VP-MCC-like tumors, matching the unique epigenetic state of late-stage hPGCs. Notably, pluripotent intermediates were neither necessary nor sufficient for MST; transformation required acquisition of a late-hPGC-like epigenetic state. Conclusions: This is the first MST model of a somatic cancer arising through an aberrant germline-to-soma transition. Our findings unify VP-MCC and germ cell cancer biology, challenge mutation- and soma-centric paradigms, and provide a tractable platform to investigate developmental and epigenetic mechanisms of oncogenesis. This MST model supports a unifying germ cell origin for both germ cell and non-germ cell somatic malignancies. Full article

Background: Primordial germ cells (PGC) are the progenitor cells of sperm and eggs during the embryonic stage. The maternal gene vasa has been widely studied for its role in PGC origin, and other genes like dead end (dnd) have also been identified. Objectives: Spotted sea bass is an important economic marine fish, and the study of its germ cell characteristics provides important basic data for future population breeding and protection. Methods: In this study, we cloned the full-length sequences of Lmvasa (2384 bp, encoding 1905 aa) and Lmdnd (1523 bp, encoding 386 aa) using RACE. Temporal and spatial expression patterns of Lmvasa and Lmdnd in embryos and gonads were analyzed by PCR, immunohistochemistry, and in situ hybridization. We also used microinjections of chimeric RNA containing GFP and Lmvasa 3′ UTR to visualize PGCs. Results: Our results showed that Lmvasa and Lmdnd are expressed primarily in early embryonic development (pre-blastula stage) and were expressed only in the gonads. Immunohistochemistry revealed abundant expression of Lmvasa and Lmdnd proteins in spermatogonia, weak expression in spermatocytes, and no expression in spermatozoa. In ovaries, both genes were expressed throughout oogenesis. Furthermore, PGCs in spotted sea bass belonged to an early localization pattern. Microinjection experiments demonstrated that Lmvasa 3′ UTR effectively labeled PGCs in embryos of spotted sea bass, zebrafish, and medaka. Conclusions: These findings may contribute to understanding PGC development in spotted sea bass and other Percidae. Full article

The capability to generate induced pluripotent stem cells (iPSCs) from adult somatic cells, enabling them to differentiate into any cell type, has been demonstrated in several studies. In humans and mice, iPSCs have been shown to differentiate into primordial germ cells (PGCs), spermatozoa, and oocytes. However, research on iPSCs in deer is novel. Despite the necessity for establishing germplasm banks from endangered cervid species, the collection and cryopreservation of gametes and embryos have proven complex for this group. Therefore, the focus of this study was to establish protocols for deriving stable iPSC lines from Blastocerus dichotomus (Marsh deer) using primary cells derived from antler, adipose tissue, or skin, with the ultimate goal of producing viable gametes in the future. To achieve this, two main reprogramming approaches were tested: (1) transfection using PiggyBac transposons (plasmid PB-TET-MKOS) delivered via electroporation and (2) lentiviral transduction using the STEMCCA system with either human (hOSKM) or murine (mOSKM) reprogramming factors. Both systems utilized murine embryonic fibroblasts (MEFs) as feeder cells. The PiggyBac system was further supplemented with a culture medium containing small molecules to aid reprogramming, including a GSK inhibitor, MEK inhibitor, ALK/TGF inhibitor, and thiazovivin. Initial colony formation was observed; however, these colonies failed to expand post-selection. Despite these challenges, important insights were gained that will inform and guide future studies toward the successful generation of iPSCs in deer. Full article

Background/Objectives: Overnutrition increases comorbidities such as gestational diabetes during pregnancy that can have detrimental consequences for both parent and progeny. We previously reported that high-fat (HF) diet and late-gestation diabetes (DM) incite mitochondrial dysfunction, oxidative stress, and cardiometabolic disease in first generation (F1) rat offspring, partially through epigenomic and transcriptomic programming. Primordial germ cells, which become the second generation (F2), are also exposed, which could incite generational risk. This study aimed to determine whether the F2 transcriptome already has genomic variation at the preimplantation embryo stage, and whether variations normalize, persist or compound in the third generation (F3). Methods: F0 female rats were fed a control or HF diet, then DM was induced in HF-fed dams on gestational day (GD)14, exposing F1 offspring and F2 primordial germ cells to hyperlipidemia, hyperglycemia and fetal hyperinsulinemia during the last third of pregnancy. F1 pups were reared by healthy dams and bred to produce F2 embryos (F2e) and F2 pups. F2 offspring were bred to produce F3 embryos (F3e). Embryos were assessed by a novel grading method, live cell imaging, and single-cell RNA sequencing. Results: Embryo grades were not different, but HF+DM F2e had more cells while F3e had fewer cells and overall fewer embryos. HF+DM F2e had similar mitochondria quantity but a downregulation of genes involved in lipid metabolism and more oxidative stress, consistent with mitochondrial dysfunction. They also had an upregulation of chromatin-remodeling genes. The predicted developmental effect is accelerated embryo aging and epigenetic drift. In contrast, HF+DM F3e had an adaptive stress response leading to increased mitochondria quantity and an upregulation of genes involved in mitochondrial respiration, metabolism, and genomic repair that led to a predicted developmental effect of delayed embryo maturation. Conclusions: Although pathways vary, both generations have metabolically linked differentially expressed genes that influence cell fate and developmental pathways. In conclusion, HF+DM pregnancy can program the early embryonic transcriptome for three generations, despite an intergenerational healthy diet. Full article

Avian leukosis virus subgroup J (ALV-J), an α-retrovirus, mediates infection by binding to the host-specific receptor chNHE1 (chicken sodium–hydrogen exchanger type 1), leading to immunosuppression and tumorigenesis, which severely threatens the sustainable development of the poultry industry. Studies have shown that the tryptophan residue at position 38 (W38) of the chNHE1 protein is the critical site for ALV-J infection. In this study, we employed the CRISPR/Cas9 system to construct a lentiviral vector targeting the W38 site of chNHE1, transfected it into chicken primordial germ cells (PGCs), and validated its antiviral efficacy through ALV-J infection assays, successfully establishing an in vitro gene-editing system for chicken PGCs. The constructed dual lentiviral vector efficiently targeted the W38 site. PGCs isolated from 5.5- to 7-day-old chicken embryos were suitable for in vitro gene editing. Stable fluorescence expression was observed within 24–72 h post-transfection, confirming high transfection efficiency. ALV-J challenge tests demonstrated that no viral env gene expression was detected in transfected PGCs at 48 h or 72 h post-infection, while high env expression was observed in control groups. After 7 days of infection, p27 antigen ELISA tests were negative in transfected groups but positive in controls, indicating that W38-deleted PGCs exhibited strong resistance to ALV-J. This study successfully generated ALV-J-resistant gene-edited PGCs using CRISPR/Cas9 technology, providing a novel strategy for disease-resistant poultry breeding and advancing avian gene-editing applications. 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

Primordial germ cells (PGCs) undergo proliferation, migration, and sexual differentiation to produce gonocytes, which eventually generate germ cells. The proteasome, which degrades most cellular proteins, is a protein complex with dozens of subunits. The proteasomal ubiquitin receptors Rpn10 and Rpn13 have been shown to play partially overlapping roles in binding ubiquitin chains in vitro and in liver function in vivo. However, the specific role of Rpn10 and Rpn13 in germ cell production remains unclear. We show here that Rpn10 and Rpn13 are each essential for germ cell production and fertility. The conditional deletion of either Rpn10 or Rpn13 in PGCs results in infertility in both male and female mice. Germ cells in testes and ovaries all decreased dramatically in the Rpn13 conditional knockout (cKO) mice. Specifically, the deletion of Rpn13 in PGCs disrupts the assembly of the 26S proteasome, reduces the number of PGCs, and blocks the meiosis of spermatocytes at the zygotene stage during prophase I; on the other hand, the deletion of Rpn10 in PGCs sharply reduces PGC migration. These results are important for understanding the roles of Rpn10 and Rpn13 in germ cell development and related reproductive diseases. Full article