Germ Cell Research Articles (Page 6)

It remains unknown about molecular mechanisms underlying the transition of somatic cells into male germ cells. It is observed that RAD21L1 transcript is upregulated during reprogramming of Sertoli cells into human spermatogonial stem cells (SSCs) by overexpressing DAZ family genes. Significantly, RAD21L1 overexpression transits Sertoli cells into phenotypic and functional human SSCs with high safety. RNA sequencing shows that DNMT1 is expressed at a higher level by RAD21L1 overexpression when Sertoli cells are reprogrammed to become human SSCs. Whole genome bisulfite sequencing elucidates that RAD21L1 modulates DNA methylation to reprogram Sertoli cells into human SSCs, and RAD21L1 interacts with DNMT1 in human SSCs generated from Sertoli cells. Intriguingly, RAD21L1 mutation results in the decreases in stemness maintenance of human SSCs and DNMT1 expression levels. Notably, RAD21L1 mutations are positively related to risk of non-obstructive azoospermia (NOA) and male infertility. Collectively, these results implicate that RAD21L1 is sufficient and effective for reprogramming human Sertoli cells to SSCs through modulating DNMT1 and RAD21L1 mutations leads to NOA. This study is of particular significance because it provides a novel molecular mechanism that reprograms human somatic cells into human SSCs and it could offer invaluable gametes for treating male infertility.

IntroductionNon-epithelial ovarian tumors (NEOTs), mainly germ cell and sex cord-stromal tumors, are rare entities that pose diagnostic and therapeutic challenges due to their heterogeneity and often nonspecific presentation. This study aimed to describe the epidemiological, clinical, pathological, and surgical characteristics of NEOTs managed at Charles Nicolle University Hospital, Tunis, over a five-year period.Materials and methodsWe conducted a retrospective descriptive study including 48 patients operated for NEOTs between January 2020 and December 2024. Clinical, radiological, surgical, and pathological data were analyzed.ResultsNEOTs represented 20.9% (48/229) of ovarian tumors. Median age at diagnosis was 35 years (IQR 28–51). Germ cell tumors accounted for 68.8% and sex cord-stromal tumors for 29.1%. Malignant tumors were rare (6.3%), all stage IA. Conservative surgery was performed in 56.2%, predominantly in germ cell tumors, while laparotomy was the main approach (87.5%). Compared with germ cell tumors, sex cord-stromal tumors occurred in older (median 51 vs. 30 years, p=0.003), more frequently postmenopausal patients (57.1% vs. 12.1%, p=0.003), and were more often >10 cm (61.5% vs. 25.8%, p=0.04). Postoperative complications occurred in 8.3%, and no recurrences were observed during follow-up.ConclusionNEOTs, though rare, accounted for a relatively high proportion of ovarian tumors in our series. They were predominantly benign and diagnosed at an early stage, with favorable outcomes. Conservative surgery should be prioritized in young women to preserve fertility. This study represents the first Tunisian series addressing all histological subtypes of NEOTs and provides a reference for future multicenter research.

Sperm analysis is the main method of assessing male reproductive function, which is not always informative in cases of infertility. In the literature, a special role in the disturbed male fertility is attributed to oxidative stress which results into damage of male germ cells. Damage of spermatozoa membranes is accompanied by the release of their DNA into the extracellular space, which is an inducer of local inflammatory reaction. In this case, the maintenance of seminal fluid homeostasis will depend on the efficiency of extracellular DNA degradation. In human beings, this function is performed by DNAse enzymes localized in all tissues and body fluids. Their role in the process of fertilization and fragmentation of spermatozoal genetic material was also noted. Excess or deficiency of DNases may lead to the development of different disorders. The aim of the present study was to establish reference intervals for ejaculate DNase 1L3 and DNase II and to search for relationships between the concentration of nucleases and sperm analysis parameters. The seminal fluid of 82 conditionally healthy men aged 18-49 years examined at the Research Institute of Immunology of South Ural State Medical University was used as a material for the study. Exclusion criteria were the presence of urogenital inflammatory disorders and sex-transmitted infections (STI). Sperm analysis was performed according to the WHO laboratory manual. Screening for STI was performed by real-time PCR. DNAse concentration in ejaculate was determined by ELISA method. Descriptive statistics, construction of histograms and reference intervals were performed in the “R” platform. Primarily, we have determined the levels of DNase 1L3 and DNase II in seminal fluid and established appropriate reference intervals. Shifts in DNase 1L3 and DNase II concentrations can most likely be considered as markers of possible pathologic conditions. In particular, an increased concentration of DNase 1L3 is an index of a pathological process associated with low sperm motility, whereas high levels of DNase II may be considered an indicator of a local inflammatory reaction.

Testicular cancer is the most common cause of cancer in the U.S. male active duty population. Advancements in surgical and chemotherapy approaches have led to a 95% 5-year survival rate across all stages. The United States Preventive Services Task Force recommends against non-symptomatic clinical screening or patient self-examination citing the high survival rate and overall low civilian incidence. We present 2 case reports of active duty individuals who died from complications of testicular cancer. Case 1 was found deceased. At autopsy, a pelvic mass was found disrupting the aorta along with hemoperitoneum. The mass was subsequently identified as a metastatic mixed germ cell tumor. Case 2 presented with orchalgia and a testicular mass, but did not attend to his ordered ultrasound before deployment. He returned to the United States with a >10 cm testis, widespread metastatic disease, and a serum beta-human chorionic gonadotropin (hCG) over 250,000. A non-seminomatous germ cell tumor was presumed, and an orchiectomy was delayed to initiate chemotherapy. He died shortly after therapy was initiated from a pulmonary hemorrhage. In this article, we discuss how unique features of the military population may impact testicular cancer care with evidence from these 2 cases along with suggestions where impactful change can be made.

Spermatogenesis is the biological process by which male sperm cells (spermatozoa) are produced in the testes. Beyond facilitating the transmission of genetic information, spermatogenesis also provides a potential framework for inter- and transgenerational inheritance of gene-regulatory states. While extensively studied in mammals, our understanding of spermatogenesis in anamniotes remains limited. Here we present a comprehensive single-cell multiomics resource, combining single-cell RNA sequencing (scRNA-seq) and single-cell chromatin accessibility (scATAC-seq) profiling, with base-resolution DNA methylome (WGBS) analysis of sorted germ cell populations from zebrafish (Danio rerio) testes. We identify the major germ cell types involved in zebrafish spermatogenesis as well as key drivers associated with these transcriptional states. Moreover, we describe localised DNA methylation changes associated with spermatocyte populations, as well as local and global changes in chromatin accessibility leading to chromatin compaction in spermatids. Notably, we identify loci that evade global chromatin compaction, and which remain accessible, suggesting a potential mechanism for the intergenerational transmission of gene-regulatory states. In summary, this high-resolution atlas of zebrafish spermatogenesis provides a valuable resource for studying vertebrate germ cell development and epigenetic inheritance, while offering a robust framework for comparative analyses across diverse models of germ cell biology.

Primordial germ cells are the embryonic precursors to sperm and egg cells, and their development is regulated by multiple molecular pathways, including small non-coding RNAs. Environmental toxicants such as vinclozolin and mono-(2-ethylhexyl) phthalate (MEHP) can alter the expression of these regulatory RNAs, affecting both the exposed individuals and their descendants. To investigate these effects, we exposed pregnant mice to vinclozolin or MEHP and collected embryonic ovaries from their offspring across three generations. Small RNA sequencing identified 3,498 microRNA and 12,078 piwi-interacting RNA sequences. Exposure led to the deregulation of 34 microRNAs and 668 piwi-interacting RNAs, with changes persisting unexposed descendants of two generations. When both parents were exposed, dysregulation was more pronounced than with maternal exposure alone, an average increase of 4.06-fold for piRNAs and 5.5-fold for microRNAs. Quantitative PCR confirmed changes in selected microRNAs. Immunofluorescence analysis showed an increase in apoptotic cells in embryonic ovaries, particularly within primordial germ cells. The number of dying cells increased 2.44-fold after vinclozolin exposure and 1.75-fold after MEHP exposure. These findings contributed to the knowledge that in utero exposure to vinclozolin or MEHP disrupts small RNA expression and increases apoptosis in the developing ovary, with effects that persist across multiple generations.Supplementary InformationThe online version contains supplementary material available at 10.1038/s41598-025-19787-w.

Fertilization ensures the flow of information from the parent to the progeny via fusion of male and female gametes orchestrated by a cascade of events guided by parental noncoding RNA (ncRNA) molecules. These parental ncRNAs play an essential role toward rewiring the germ cell profile to make them compatible for successful fertilization, thereby resulting in the formation of the zygote. They further modulate the zygotic profile to support the postfertilization events. In this work, an in-depth meta-analysis of small and long RNA-seq data corresponding to sperm, oocyte, and one-cell stage zygote of Mus musculus has been performed, followed by subsequent wet bench experiments. Our findings provide a comprehensive long noncoding RNA (lncRNA) and microRNA (miRNA) profile contributed by the parental gametes. Further, a set of novel lncRNAs have been identified, which have a potential role toward modulating sperm and oocyte fertility in the pre-fertilization stage. Moreover, a fine-tuned miRNA expression dynamics has been observed between the germ cells and the zygote to increase the competency of the germ cells for fertilization in the pre-fertilization stage. Its subsequent effects have been observed on early embryonic development in the postfertilization stage.

We aimed to investigate racial/ethnic, age-onset, and sex disparities in tumor genomic profiles across 34 solid cancer types. We analyzed tumor genomic and clinical data from 104,399 patients with 34 solid cancer types from the GENIE Consortium (2011-2023). Patients were classified by race/ethnicity (non-Hispanic White [NHW], non-Hispanic Black [NHB], Hispanic, Asian or Pacific Islander [API], and other/unknown), age at onset (<50, 50-69, ≥70 years), and sex. We assessed the prevalence and spectrum of somatic mutations and compared tumor mutational burden (TMB) across groups using adjusted regression models. Significant racial/ethnic and age-onset differences in TMB were observed in 15 and 21 cancer types. Males had higher TMB in non-small cell lung cancer (NSCLC), melanoma, hepatobiliary, non-melanoma skin, and germ cell cancers, while females had higher TMB in colorectal, glioma, and head & neck cancer. Notable racial/ethnic disparities were found in frequently mutated genes. Compared with NHW, API [OR=0.23 (95%CI=0.19-0.29)] and Hispanic [0.56 (0.44-0.71)] patients had lower frequencies of KRAS mutations in NSCLC, while NHB patients had higher frequencies of KRAS in colorectal cancer [1.61 (1.37-1.90)], TP53 in breast cancer [1.77 (1.51-2.07)], and endometrial cancer [2.28 (1.66-3.12)]. Older patients generally had more mutated genes, although some genes in seven cancer types showed higher frequencies in patients under 50. Distinct spectrums of somatic mutations exist across various racial/ethnic, age-onset, and sex groups. This study presents a pan-cancer assessment of disparities in tumor genomic profiles and can enhance our understanding of disparities in cancer etiology and prognosis.

Despite an incidence increase in recent decades, the etiology of testicular germ cell tumors (TGCT) remains poorly understood. The hypothesis of a two-stage development, combining initial alteration in utero followed by malignant transformation later in life, has been suggested. This study examined the association between cumulative lifetime occupational and para-occupational solvent exposure and TGCT risk. The French multicenter case-control study TESTIS included 454 cases and 670 controls. Participants provided information on their occupational history; participants' mothers (N = 547) provided information on their own and the father's occupational history. Solvent exposure was assessed by using the Matgéné job-exposure matrices. The influence of the parental and subject's occupational exposures over the lifetime and at different periods (i.e. fetal life/infancy; childhood; adolescence; subject's exposure) on TGCT was examined. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by using conditional logistic regression models. An OR for TGCT of 1.03 (95% CI 0.59-1.79) was found for the lifetime solvent exposure. When each period was examined individually, the results showed an increased TGCT risk in adult males who were occupationally exposed to trichloroethylene (OR = 3.09; 95% CI 1.25-7.65); fuels and petroleum-based solvents (OR = 1.91; 95% CI 1.21-3.02); diesel, kerosene, and fuel oil (OR = 2.26; 95% CI 1.16-4.41); and ketones and esters (OR = 1.66; 95% CI 1.02-2.71), and suggested a positive association with solvent exposure during adolescence (OR = 1.77; 95% CI 0.95-3.31). Overall, this study did not suggest a substantial role of cumulative lifetime solvent exposure and TGCT risk. The results showed an increased TGCT risk associated with solvent exposure during adulthood. Indirect exposure to certain solvents during adolescence might also promote TGCT development.

Microsurgical testicular sperm extraction (microTESE) with intracytoplasmic sperm injection (ICSI) represents the current standard treatment for nonobstructive azoospermia (NOA). However, cures remain unavailable for NOA patients lacking retrievable haploid cells. mRNA supplementation could be a potential treatment for genetic defects leading to impaired spermatogenesis. Lipid nanoparticles (LNPs) have emerged as mRNA delivery vehicles with minimal risk of genome integration; however, their ability to selectively deliver mRNA to specific cell types remains limited. To overcome this, microRNA (miRNA) target sequences were incorporated into mRNA constructs to restrict expression specifically to germ cells. Using pyruvate dehydrogenase E1 subunit alpha 2 (PDHA2) knockout mice as an NOA model with meiotic arrest, we demonstrate that LNP-mediated delivery of Pdha2 mRNA enables the resumption and completion of meiosis, restores sperm production, and facilitates the generation of healthy fertile offspring via ICSI. Whole-genome sequencing of the offspring confirmed the absence of large-scale genomic abnormalities. Our results provide proof of concept for a safe and effective chemically synthesized LNP-based mRNA therapy with miRNA-regulated germ cell specificity, offering a promising therapeutic approach to treating male infertility caused by spermatogenesis arrest.

IntroductionTesticular cytofunctional defects are among the most hazardous effects of cancer chemotherapies. Propolis mitigates the fertility problems associated with gonadotoxic agents through its redox stabilizing, anti-apoptotic, and cytoprotective properties due to presence of bioactive agents identified in our study by gas chromatography–mass spectrometry analysis including, flavonoids, terpenes, aliphatic and aromatic compounds, and amino acids. Herein, we investigated the potential reversal effects of aqueous propolis on busulfan-induced reproductive abnormalities in adult rats.MethodsThirty rats were randomly assigned to five experimental groups, with six animals per group, for duration of 6 weeks. The control group received only the vehicle daily through oral gavage. The DMSO group was given a single intraperitoneal injection of DMSO. The busulfan group received a single intraperitoneal injection of busulfan at a dose of 20 mg/kg body weight, followed by daily oral gavage. The propolis group was administered propolis daily via oral gavage at a dose of 100 mg/kg body weight. In the busulfan + propolis group, rats received a single intraperitoneal injection of busulfan at 20 mg/kg body weight, combined with daily oral gavage of propolis at a dose of 100 mg/kg body weight.Results and discussionBusulfan exposure led to a decrease in serum levels of follicle-stimulating hormone, testosterone, and estradiol 17β, along with an increase in luteinizing hormone. It negatively affected sperm outcomes, causing a decline in sperm count and the percentages of live, normal, and motile sperm, while increasing the percentages of dead and abnormal sperm. Furthermore, busulfan disrupted the testicular defense system, as indicated by elevated testicular malondialdehyde levels and reductions in testicular nitric oxide and reduced glutathione levels, catalase and superoxide dismutase activities, as well as serum total antioxidant capacity. Marked histopathological changes were observed, in concomitant with strong immunoreactivity for proliferating cell nuclear antigen and caspase-3 in germ cells. Propolis supplementation effectively mitigated all these abnormalities in busulfan-intoxicated rats. Propolis is suggested as a potential complementary adjuvant for managing busulfan-induced reproductive dysfunction, owing to its reproductive hormone-modulating, redox-stabilizing, sperm-protective, and anti-apoptotic properties.

This paper reports the clinical case of a 26-year-old adult female diagnosed with a mature ovarian teratoma. Ovarian teratomas are germ cell tumors composed of tissues derived from all three embryonic layers, more frequently seen in young women but rare in adults. The patient presented with severe lower abdominal pain; imaging revealed a 20 cm heterogeneous mass in the right ovary with hyperechoic areas suggestive of fat and calcifications. Emergency laparotomy with cystectomy and ovarian tissue preservation was performed due to suspected torsion. Histopathological examination confirmed a mature teratoma without malignancy. The postoperative course was favorable, with preserved ovarian function and no tumor recurrence during follow-up. This case highlights the relevance of early diagnosis and timely surgical management to prevent complications and preserve fertility in young women.

Infertility affects ~ 15% of couples globally, with male factors contributing to ~ 50% of cases. Male infertility comes from a variety genetic, hormonal, environmental, and lifestyle factors. Yet, a large proportion of cases are idiopathic and have no identifiable cause. Recent advances highlight the critical role of microRNAs (miRNAs), small non-coding RNAs that regulate gene expression at the post-transcriptional level, in male reproductive health. miRNAs are pivotal in spermatogenesis, sperm maturation, and testicular function, influencing processes such as cell cycle regulation, apoptosis, and differentiation. Altered miRNA expression has been linked to many types of male infertility, such as oligozoospermia (low sperm count), asthenozoospermia (low motility), azoospermia(no sperm) and teratozoospermia(abnormal morphology). Notably, miRNAs like miR-34c, miR-21, and miR-449 play essential roles in germ cell proliferation, meiotic progression, and spermiogenesis, while others, such as miR-210 and miR-122, impact sperm motility and DNA integrity.Their stability in biological fluids positions miRNAs as promising non-invasive biomarkers for diagnosing male infertility. miRNA-based diagnostics significantly reduce the need for invasive testicular biopsies in men with azoospermia, enabling earlier, less invasive, and more accurate identification of underlying spermatogenic defects. Furthermore, miRNA-targeted therapies hold promise for restoring spermatogenesis in select cases, potentially improving fertility outcomes for affected patients. Moreover, therapeutic approaches targeting miRNA pathways, including miRNA mimics and inhibitors, offer innovative solutions to restore reproductive function. However, challenges such as complex miRNA networks, delivery system inefficiencies, and inter-individual variability hinder clinical translation. The various functions of miRNAs in male infertility are highlighted in this review, along with their potential for diagnosis, prognosis, and treatment.

ABSTRACTScrotal lymphedema is a rare late complication of testicular cancer treatment, with most reported cases occurring in the early postoperative period. Massive scrotal elephantiasis manifesting more than a decade after postchemotherapy retroperitoneal lymph node dissection (pc‐RPLND) has not previously been described. We present a 44‐year‐old Aboriginal man with progressive scrotal swelling 12 years after treatment for Stage IIIc nonseminomatous germ cell tumor, including inguinal orchidectomy, four cycles of bleomycin, etoposide, and cisplatin chemotherapy, and pc‐RPLND for residual teratoma. The patient delayed presentation due to embarrassment and uncertainty about accessing care in his remote community. Examination revealed massive scrotal elephantiasis. Imaging and tumor markers excluded recurrence or infection. He underwent scrotectomy with primary reconstruction, yielding 2076 g of tissue showing lymphangiectasia, dermal fibrosis, and chronic inflammation without malignancy. Postoperative recovery was uneventful, with marked improvements in mobility and quality of life. This case illustrates an exceptionally rare, delayed manifestation of massive scrotal lymphedema following pc‐RPLND, likely due to combined surgical disruption of lymphatic drainage and bleomycin‐induced endothelial injury. It underscores the need for long‐term surveillance, patient education regarding late complications, and culturally safe, coordinated cancer care, particularly for Indigenous patients in rural and remote settings.

Intracranial germ cell tumors (ICGCTs) represent a rare subset of neoplasms with notably higher incidence in Asian cohorts compared to Western counterparts. Diagnostic delays in ICGCT, frequently associated with endocrine presentations, have previously been documented. However, factors contributing to delays, as well as the implications for clinical outcomes, remain insufficiently elucidated. This study aims to evaluate presentations, diagnostic intervals, and long-term endocrine sequelae in children with ICGCT. This retrospective cohort study included all children diagnosed with ICGCT from 2008 to 2023 in Hong Kong. Clinical, pathological, and endocrine data were collected with treatment outcomes and survival analyzed. Prolonged diagnostic interval was defined as > 6 months from symptom onset. A total of 104 children with ICGCT (59.6% males, median age 12.6 years, follow-up 6.8 years) were included. About 64.4% had germinoma. Endocrine deficits were present in 63.5% at diagnosis. The median diagnostic interval was 3 months. About 32.7% had prolonged diagnostic intervals, particularly for suprasellar tumors and those presenting with endocrinopathies. Inconclusive MRI, as well as caveats in tumor biopsy, also contributed to delayed diagnosis. Diagnostic interval had no impact on overall survival and progression-free survival, but children with diagnostic delay tend to be shorter. At follow-up, 66.3% had persistent endocrinopathies, in addition to 40.8% being overweight/obese and 60% having low bone mineral density. Our study highlighted patient-related, physician-related, and tumor-related delays in the diagnosis of pediatric ICGCT. Although there was no impact on mortality, children with diagnostic delay tend to be shorter. Surveillance of endocrinopathies alongside assessment of weight status and bone health is essential.

Differentiation of spermatogonial stem cells (SSCs) on decellularized biological scaffolds has emerged as a novel approach in tissue engineering and male infertility treatment. Testis-derived extracellular matrix (ECM) scaffolds provide a natural microenvironment that can support SSC culture and differentiation. In this study, we compared the efficiency of different detergents for the decellularization of fresh and frozen human testicular tissues. Human testicular tissue samples were divided into 2 groups: fresh and frozen at -80 °C. Cellular decellularization was performed using concentrations of 0.5% and 1% sodium dodecyl sulfate (SDS) and Triton x100 alone and in combination. The extent of cell removal and reduction in cell DNA content was examined using histological studies and one-way ANOVA statistical method. Frozen tissues exposed sequentially to 1% SDS for 24 h followed by 1% Triton X-100 for 24 h showed the highest efficiency in removing cellular components while maintaining ECM integrity, compared with fresh tissues. Moreover, frozen testicular matrices demonstrated greater resistance to detergent-induced damage than fresh matrices. Both detergent concentration and tissue condition (fresh vs. frozen) are critical determinants of scaffold quality in testicular decellularization. Optimizing these parameters may facilitate the development of natural testis-derived scaffolds for reproductive tissue engineering. In the future, seeding germ cells from patients with non-obstructive azoospermia onto these optimized scaffolds under differentiation-inducing conditions may provide a promising strategy for male infertility treatment.

In the United States, ovarian cancer is the second most common form of gynecologic cancer and the second leading cause of gynecologic cancer death. It is a heterogeneous disease with many different types and subtypes. The most common variety (70%-80%) is the high-grade serous epithelial tumor. A positive family history and/or the presence of susceptibility genes (BRCA1, BRCA2, and mismatch repair genes) increase the risk for developing the disease. Due to the lack of effective screening tools, even in those with known increased risk, most ovarian cancers are diagnosed at advanced stages. Diagnosis and accurate staging usually require tissue sampling and extensive debulking surgery performed by a surgeon who specializes in gynecologic oncology. Combination chemotherapy, before or after surgery, or as primary treatment for advanced disease is commonly needed. Mortality rates vary by stage, grade, and type of tumor. For the most common histotypes, due to the presence of advanced disease at presentation in most individuals, overall death rates remain high. Survival is better with some of the less common subtypes including sex cord stromal, germ cell and borderline epithelial ovarian tumors.

Fertility preservation is a growing priority in the management of young women with rare ovarian tumors, including malignant ovarian germ cell tumors (MOGCTs), sex cord-stromal tumors (SCSTs), and borderline ovarian tumors (BOTs). These malignancies often affect adolescents and women of reproductive age and are frequently treated with fertility-sparing surgery and platinum-based chemotherapy. Our objective is to systematically evaluate reproductive outcomes, menstrual function recovery, and fertility preservation strategies in female survivors of rare cancers such as MOGCTs, SCSTs, and BOTs. A systematic review was conducted in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. PubMed, Scopus, and BioMed Central were searched for studies published between 2005 and 2025. Eligible studies included observational or cohort designs reporting on fertility status, menstrual recovery, and reproductive outcomes following treatment for rare tumors. A total of 24 studies met the inclusion criteria. Data extraction included fertility preservation approaches, rates of natural versus assisted conception, menstrual function outcomes, and the incidence of premature ovarian insufficiency (POI). Fertility-sparing surgery with or without chemotherapy was the most applied fertility preservation strategy. Spontaneous conception was predominant, with pregnancy rates ranging from 50% to over 90%. Menstrual recovery occurred in 71-100% of patients. POI was rare in solid tumor survivors but occurred in up to 87% of leukemia patients. Long-term follow-up showed durable ovarian function and no increase in cancer recurrence. Ovarian tissue cryopreservation (OTC) and oocyte retrieval were effective in selected high-risk cases. Fertility preservation in patients with rare ovarian malignancies is both safe and effective. Early fertility counseling and individualized, risk-adapted strategies should be integrated into standard cancer care, especially for patients at high risk for gonadal failure.

Unusual Presentation of a Common Disease: Metastatic Germ Cell Tumor in the Brain

The Amazon guppy, Poecilia bifurca, is a small live-bearing fish. The close relatives Poecilia reticulata, Poecilia picta, and Poecilia parae all share the same sex chromosome system, but with substantial diversity in the degree of Y degeneration and the extent of X chromosome dosage compensation. In order to identify if P. bifurca shares the same sex chromosome system, we built a female (XX) draft genome with 55X coverage of PacBio HiFi data, resulting in a 785 Mb assembly with 94.4% BUSCO completeness. We used this genome and found that P. bifurca shares the same sex chromosomes as related species and shows substantial Y chromosome degeneration. We combined this with RNA-Seq data and found similar expression of X-linked genes between sexes, revealing that P. bifurca also exhibits complete X chromosome dosage compensation. We further identify 11 putative autosome-to-Y gene duplications, 5 of which show gene expression in guppy male germ cells.