Background The cellular basis of testicular development and spermatogenesis for the extreme sperm density in chickens(100-fold higher than mammals)remains poorly defined.A comprehensive understanding of the molecular ...Background The cellular basis of testicular development and spermatogenesis for the extreme sperm density in chickens(100-fold higher than mammals)remains poorly defined.A comprehensive understanding of the molecular characteristics driving poultry testicular development is crucial for explaining this enhanced spermatogenic capacity.Results Here,we first established a single-cell transcriptome profile of chicken testes from hatching to maturity,identifying the dynamic transcriptional characteristics of germ cell fate transition and exploring the developmental characteristics of Sertoli cells and Leydig cells.Multi-species comparisons revealed a higher proportion of germ cells and the unique adaptations of Sertoli cells in chicken testes.Most importantly,our results demonstrated that Sertoli cells dominated in somatic composition of mature chicken testes,and proliferating Sertoli cells persisted in chicken testes even after sexual maturity,while no proliferating Sertoli cells in mammals.We also found a richer interaction network between chicken testicular cells,especially the specific activation of Sertoli cell interaction signals,such as TGF-β,BMP,EGF,and activin.These adaptations of Sertoli cells may support the spermatogenic superiority in chickens.Additionally,our results indicated that cAMP responsive element binding protein 5(CREB5)played a crucial role in maintaining the maturation and function of chicken Sertoli cells,and circadian rhythm promoted testosterone secretion and the development of Leydig cells.Conclusion Our study revealed that the sustained proliferative capacity of Sertoli cells,their enriched signaling network,and the regulatory roles of CREB5 and circadian rhythms collectively represented unique testicular adaptations in chickens.These findings may hold extraordinary significance in understanding the molecular characteristics of poultry testicular development,and provide a plausible framework for explaining enhanced spermatogenesis in poultry.展开更多
As prepubertal boys do not yet produce spermatozoa,they cannot rely on sperm cryopreservation for fertility preservation before gonadotoxic therapy,such as high-dose alkylating agents or radiotherapy in the case of ch...As prepubertal boys do not yet produce spermatozoa,they cannot rely on sperm cryopreservation for fertility preservation before gonadotoxic therapy,such as high-dose alkylating agents or radiotherapy in the case of childhood cancers.According to the current guidelines,cryopreservation of testicular biopsies containing spermatogonial stem cells(SSCs)may be proposed to high-risk patients for potential later therapeutic use to fulfill the patients’wish for a biological child.One promising technique for human in vitro spermatogenesis and in vitro propagation of human SSCs is microfluidic(MF)culture,in which cells or tissues are subjected to a continuous flow of medium.This provides exact control over such parameters as nutrient content and gradients,as well as the removal of waste metabolites.While MF has been shown to maintain tissues and cell populations of organs for longer than conventional in vitro culture techniques,it has not been widely used for testicular in vitro culture.MF could advance human testicular in vitro culture and is also applicable to reprotoxicity studies.This review summarizes the findings and achievements of testis-on-chip(ToC)setups to date and discusses the benefits and limitations of these for spermatogenesis in vitro and toxicity assessment.展开更多
Spermatogenesis is a fundamental process that requires a tightly controlled epigenetic event in spermatogonial stem cells(SSCs).The mechanisms underlying the transition from SSCs to sperm are largely unknown.Most stud...Spermatogenesis is a fundamental process that requires a tightly controlled epigenetic event in spermatogonial stem cells(SSCs).The mechanisms underlying the transition from SSCs to sperm are largely unknown.Most studies utilize gene knockout mice to explain the mechanisms.However,the production of genetically engineered mice is costly and time-consuming.In this study,we presented a convenient research strategy using an RNA interference(RNAi)and testicular transplantation approach.Histone H3 lysine 9(H3K9)methylation was dynamically regulated during spermatogenesis.As Jumonji domain-containing protein 1A(JMJD1A)and Jumonji domain-containing protein 2C(JMJD2C)demethylases catalyze histone H3 lysine 9 dimethylation(H3K9me2),we firstly analyzed the expression profile of the two demethylases and then investigated their function.Using the convenient research strategy,we showed that normal spermatogenesis is disrupted due to the downregulated expression of both demethylases.These results suggest that this strategy might be a simple and alternative approach for analyzing spermatogenesis relative to the gene knockout mice strategy.展开更多
Morphology of the male reproductive system, chromosome behaviors during meiosis and spem tail structures in Homoptera and Heteroptera are compared in this paper. The sheathed testis is found in Fulgoroidea and Heterop...Morphology of the male reproductive system, chromosome behaviors during meiosis and spem tail structures in Homoptera and Heteroptera are compared in this paper. The sheathed testis is found in Fulgoroidea and Heteroptera, and unsheathed testis occurs in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Psyloidea, Aphidoidea, Aleyrodoidea and Coccoidea. The testis also can be divide into three types by the shape of testicular follicles. The sphere-shaped type is found in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Aphidoidea and Aleyrodoidea, the tube-shaped type observed in Fulgoroidea, Psyloidea and Coccoidea, and the lamella-shaped type represented by Heteroptera. It is suggested the unsheathed testis may be the primitive type in Homoptera. Meiosis can be divided into 6 type at least, i.e. 1） Cicadoid type; 2） Fulgoroid type; 3） Psyloid type; 4） Aphidoid type; 5） Aleyrodoid type; and 6） Coccoid type. At least four groups exhibit a diffuse stage during meiosis prophase l, they are Psyloidea, Fulgoroidea, Coccoidea and Heteroptera. Sperm tail structures are similar to those reported from other insects with a typical 9＋9＋2 axoneme except that in Aleyrodoidea and Coccoidea whose sperm tail is degenerated.展开更多
Marchantia polymorpha,a model liverwort,provides a valuable system for investigating the evolution of plant sexual reproduction.To explore the cellular landscape of its reproductive structures,we generate a single-nuc...Marchantia polymorpha,a model liverwort,provides a valuable system for investigating the evolution of plant sexual reproduction.To explore the cellular landscape of its reproductive structures,we generate a single-nucleus transcriptomic atlas of the antheridiophore,archegoniophore,and sporophyte.Using singlenucleus RNA sequencing(snRNA-seq),we capture over 30,000 high-quality nuclei and identify distinct cel populations.In the male organ,we characterize stages of spermatogenesis from early antheridium cells to mature sperm,revealing dynamic transcriptional programs including cell cycle regulation,chromatin remodeling,and calcium signaling.In the female organ,we define cell types including archegonial layers and secondary central cells.Sporophyte clusters are annotated as spores,elaters,capsule wall,foot,and seta cells,with transcriptional signatures related to structural support,stress response,and reproductive functions.Cross-species analysis indicates that capsule wall cells in liverworts are similar to tapetum cells.Notably,foot cells exhibit high expression of genes involved in sporopollenin biosynthesis and signaling pathways,serving as a central hub that mediates communication between the maternal gametophyte and the developing sporophyte.This study provides a comprehensive cellular and molecular map of M.polymorpha reproductive organs and sporophyte,establishing a framework for investigating the development and evolution of sexual reproduction in early land plants.展开更多
目的采用文献计量学方法,分析2004年—2024年支持细胞在精子发生领域的研究热点和发展趋势。方法检索2004年—2024年Web of Science核心数据库、中国知网收录的支持细胞相关研究,共筛选出5679篇英文文献和455篇中文文献,采用CiteSpace...目的采用文献计量学方法,分析2004年—2024年支持细胞在精子发生领域的研究热点和发展趋势。方法检索2004年—2024年Web of Science核心数据库、中国知网收录的支持细胞相关研究,共筛选出5679篇英文文献和455篇中文文献,采用CiteSpace软件对发文量、研究机构、作者合作网络及关键词进行系统性分析。结果英文关于支持细胞的研究发文量显著多于中文,且英文研究机构如Population Council在国际合作网络中处于核心地位,而中文研究机构的国际合作相对较少。英文作者在研究持续性、团队协作及发文量方面较有优势,而中文作者的研究多为短期或独立完成。关键词分析表明,英文研究主要聚焦于支持细胞的分子机制如基因表达、血睾屏障、精原干细胞等,而中文研究则更多关注传统动物模型及新兴领域如中药研究、铁死亡、信号通路等。结论基于文献计量分析结果,当前支持细胞在精子发生领域的研究中,英文文献在发文规模、合作网络、研究连续性及国际影响力上均显著占优,其研究已深入分子机制并整合多种前沿技术;中文研究则侧重于传统动物模型,并聚焦于中药干预与铁死亡等新兴方向。未来,中文研究需加强国际合作、稳定团队建设、系统阐释精子发生调控网络,并推动中药多靶点作用机制与现代生殖生物学的深度融合,以提升整体研究水平。展开更多
To investigate the effect of arsenic on spermatogenesis. Methods: Mature (4 months old) Wistar rats were intraperitoneally administered sodium arsenite at doses of 4, 5 or 6 mg-kg^-day1 for 26 days. Different varietie...To investigate the effect of arsenic on spermatogenesis. Methods: Mature (4 months old) Wistar rats were intraperitoneally administered sodium arsenite at doses of 4, 5 or 6 mg-kg^-day1 for 26 days. Different varieties of germ cells at stage VII seminiferous epithelium cycle, namely, type A spermatogonia (ASg), preleptotene spermatocytes (pLSc), midpachytene spermatocytes (mPSc) and step 7 spermatids (7Sd) were quantitatively evaluated, along with radioimmunoassay of plasma follicle-stimulating hormone (FSH), lutuneizing hormone (LH), testosterone and assessment of the epididymal sperm count. Results: In the 5 and 6 mg/kg groups, there were significant dose-dependent decreases in the accessory sex organ weights, epididymal sperm count and plasma concentrations of LH, FSH and testosterone with massive degeneration of all the germ cells at stage VII. The changes were insignificant in the 4 mg/kg group. Conclusion: Arsenite has a suppressive influence on spermatogenesis and gonadotrophin and testosterone release in rats.展开更多
Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors. Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family a...Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors. Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family and testicular hormones. Testicular cytokines and growth factors (such as IL-1, IL-6, TNF, IFN-γ, LIF and SCF) were shown to affect both the germ cell proliferation and the Leydig and Sertoli cells functions and secretion. Cytokines and growth factors are produced by immune cells and in the interstitial and seminiferous tubular compartments by various testicular cells, including Sertoli, Leydig, peritubular cells, spermatogonia, differentiated spermatogonia and even spermatozoa. Corresponding cytokine and growth factor receptors were demonstrated on some of the testicular cells. These cytokines also control the secretion of the gonadotropins and testosterone in the testis. Under pathological conditions the levels of pro-inflammatory cytokines are increased and negatively affected spermatogenesis. Thus, the expression levels and the mechanisms involved in the regulation of testicular paracrine/autocrine factors should be considered in future therapeutic strategies for male infertility.展开更多
Aim： To investigate the expression and subcellular localization of chemokine-like factor superfamily 2 （CKLFSF2） in human testis and its potential role in spermatogenesis. Methods： A specific polyclonal antibody a...Aim： To investigate the expression and subcellular localization of chemokine-like factor superfamily 2 （CKLFSF2） in human testis and its potential role in spermatogenesis. Methods： A specific polyclonal antibody against CKLFSF2 was raised. The expression and cellular localization of CKLFSF2 in the seminiferous tubules was checked by immunohistochemistry method. Also, in situ hybridization was applied to localize the mRNA distribution. The EGFP- CKLFSF2 fusion protein was expressed in COS-7 cells to localize its subcellular location in vitro. In addition, the abnormal expression of CKLFSF2 in testes of patients with male infertility was assayed by reverse transcription polymerase chain reaction （RT-PCR） and immunohistochemistry methods. Results： Having a close correlation with spermatogenesis defects, CKLFSF2 was specifically expressed in meiotic and post-meiotic germ cells, which were localized to the endoplasmic reticulum （ER） near the Golgi apparatus. Conclusion： CKLFSF2 could play important roles in the process of meiosis and spermiogenesis, and might be involved in the vesicular transport or membrane apposition events in the endoplasmic reticulum.展开更多
The effects of diabetes mellitus include long-term damages, dysfunctions, and failures of various organs. An important complication of diabetes is the disturbance in the male reproductive system. Glucose metabolism is...The effects of diabetes mellitus include long-term damages, dysfunctions, and failures of various organs. An important complication of diabetes is the disturbance in the male reproductive system. Glucose metabolism is an important event in spermatogenesis. Moreover, glucose metabolism is also important for maintaining basic cell activity, as well as specific functions, such as motility and fertilization ability in mature sperm. Diabetic disease and experimentally induced diabetes both demonstrated that either type 1 diabetes or type 2 diabetes could have detrimental effects on male fertility, especially on sperm quality, such as sperm motility, sperm DNA integrity, and ingredients of seminal plasma. Epigenetic modifications are essential during spermatogenesis. The epigenetic regulation represents chromatin modifications including DNA methylation, histone modifications, remodeling of nucleosomes and the higher-order chromatin reorganization and noncoding RNAs. If spermatogenesis is affected during the critical developmental window, embryonic gonadal development, and germline differentiation, environmentally-induced epigenetic modifications may become permanent in the germ line epigenome and have a potential impact on subsequent generations through epigenetic transgenerational inheritance. Diabetes may influence the epigenetic modification during sperm spermatogenesis and that these epigenetic dysregulation may be inherited through the male germ line and passed onto more than one generation, which in turn may increase the risk of diabetes in offspring.展开更多
Aim:To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii(maca)on spermatogenesis in adult male rats.Methods;Male rats received an aqueous extract of the root(66.7 mg ...Aim:To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii(maca)on spermatogenesis in adult male rats.Methods;Male rats received an aqueous extract of the root(66.7 mg in onemL)twice a day for 14 consecutive days.Results:Treatment with Lepidium meyenii resulted in an increase in theweights of testis and epididymis but not the seminal vesicle weight.The length and frequency of stages IX-XIV seminif-erous tubules,where mitosis occurred,were increased and stages I-VI were reduced in rats treated with Lepidiummeyenii.Conclusion;The Lepidium meyenii root invigorates spermatogenesis in male rats by acting on its initialstages(IX-XIV).展开更多
The blood-testis barrier （BTB） is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferou...The blood-testis barrier （BTB） is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferous tubes. It is a compound proteinous structure, composed of several types of cell junctions including tight junctions （TJs）, adhesion junctions and gap junctions （GJs）. Some of the junctional proteins function as structural proteins of BTB and some have regulatory roles. The deletion or functional silencing of genes encoding these proteins may disrupt the BTB, which may cause immunological or other damages to meiotic and postmeiotic cells and ultimately lead to spermatogenic arrest and infertility. In this review, we will summarize the findings on the BTB structure and function from genetically-modified mouse models and discuss the future perspectives.展开更多
We investigated whether letrozole （2.5 mg day-1） improves sperm count in non-obstructive azoospermia （NOA） patients. Four men were included in this study, and they had folliculo-stimulating hormone and other hormo...We investigated whether letrozole （2.5 mg day-1） improves sperm count in non-obstructive azoospermia （NOA） patients. Four men were included in this study, and they had folliculo-stimulating hormone and other hormone levels within the normal range and no varicoceles or chromosomal aberrations. These four patients were administered letrozole for 3 months. Sperm count, testicular volume, gonadotropin, testosterone （T） and estradiol （E2） blood levels were assessed before, during and 1 week after the suspension of treatment. All patients showed spermatozoa in their ejaculate, increased gonadotropin and T levels and lower E2 levels （P〈0.05 in all cases）, when letrozole was administered. This suggests that letrozole treatment might improve sperm count in an NOA sub-population; however, more studies, including the proper controls, are needed to confirm its efficacy.展开更多
Aim： To determine whether vasectomy away from the epididymal tail （via the inguinal canal） in rabbits can reduce the early postoperative effects on spermatogenesis. Methods： Twenty-nine normal male Japanese white ...Aim： To determine whether vasectomy away from the epididymal tail （via the inguinal canal） in rabbits can reduce the early postoperative effects on spermatogenesis. Methods： Twenty-nine normal male Japanese white rabbits （aged 4- 6 months） were subjected to unilateral close-ended （conventional） or open-ended （the cut end of the juxta-epididymal vas deferens not ligated） vasectomy via the inguinal canal. Ten days and 3 months after operation, testes, epididymides and vasa deferentia were removed and methacrylate resin-embedded sections prepared. The histology of the testis, epididymis and vas deferens was examined under light microscope, and the volume and diameter of the seminiferous tubules were quantitatively studied using stereological methods. Results： Neither of the methods of vasectomy led to apparent damage to spermatogenesis on the vasectomized side in comparison with the contralateral shamoperated side, but the juxta-epididymal vas deferens on the vasectomized side was highly distended and contained numerous sperm 3 months after operation. Conclusion： Vasectomy away from the cauda epididymis has no significant early postoperative effects on spermatogenesis in rabbits.展开更多
Both pulsatile gonadotropin-releasing hormone （GnRH） infusion and combined gonadotropin therapy （human chorionic gonadotropin and human menopausal gonadotropin [HCG/HMG]） are effective to induce spermatogenesis in...Both pulsatile gonadotropin-releasing hormone （GnRH） infusion and combined gonadotropin therapy （human chorionic gonadotropin and human menopausal gonadotropin [HCG/HMG]） are effective to induce spermatogenesis in male patients with congenital hypogonadotropic hypogonadism （CH H）. However, evidence is lacking as to which treatment strategy is better. This retrospective cohort study included 202 patients with CHH： twenty had received pulsatile GnRH and 182 had received HCG/HMG. Patients had received therapy for at least 12 months. The total follow-up time was 15.6 ± 5.0 months （range： 12-27 months） for the GnRH group and 28.7 ± 13.0 months （range： 12-66 months） for the HCG/HMG group. The median time to first sperm appearance was 6 months （95% confidence interval [CI]： 1.6-10.4） in the GnRH group versus 18 months （95% Ch 16.4-20.0） in the HCG/HMG group （P〈 0.001）. The median time to achieve sperm concentrations 〉5 x 106 m1-1 was 14 months （95% Ch 5.8-22.2） in the GnRH group versus 27 months （95% Ch 18.9-35.1） in the HCG/HMG group （P 〈 0.001）, and the median time to concentrations 〉10 x 106 m1-1 was 18 months （95% Ch 10.0-26.0） in the GnRH group versus 39 months （95% CI unknown） in the HCG/HMG group. Compared to the GnRH group, the HCG/HMG group required longer treatment periods to achieve testicular sizes of 〉4 ml, 〉8 ml, 〉12 ml, and 〉16 ml. Sperm motility （a ＋ b ＋ c percentage） evaluated in semen samples with concentrations 〉1 × 106 ml-1 was 43.7% ± 20.4% （16 samples） in the GnRH group versus 43.2% ± 18.1% （153 samples） in the HCG/HMG group （P= 0.921）. Notably, during follow-up, the GnRH group had lower serum testosterone levels than the HCG/HMG group （8.3 ±4.6 vs 16.2 ± 8.2 nmol 1-1, P 〈 0.001）. Our study found that pulsatile GnRH therapy was associated with earlier spermatogenesis and larger testicular size compared to combined gonadotropin therapy. Additional prospective randomized studies would be required to confirm these findings.展开更多
To clarify the functions and mechanism of stimulated by retinoic acid gene 8 （Stra8） in spermatogenesis, we analyzed the testes from Stra8 knockout and wild-type mice during the first wave of spermatogenesis. Compar...To clarify the functions and mechanism of stimulated by retinoic acid gene 8 （Stra8） in spermatogenesis, we analyzed the testes from Stra8 knockout and wild-type mice during the first wave of spermatogenesis. Comparisons showed no significant differences in morphology and number of germ cells at 11 days postpartum, while 21 differentially expressed genes （DEGs） associated with spermatogenesis were identified. We speculate that Stra8 performs many functions in different phases of spermatogenesis, such as establishment of spermatogonial stem cells, spermatogonial proliferation and self-renewal, spermatogonial differentiation and meiosis, through direct or indirect regulation of these DEGs. We therefore established a preliminary regulatory network of Stra8 during spermatogenesis. These results will provide a theoretical basis for further research on the mechanism underlying the role of Stra8 in spermatogenesis.展开更多
Mammalian spermatogenesis contains three continuous and organized processes, by which spermatogonia undergo mitosis and differentiate to spermatocytes, follow on meiosis to form haploid spermatids and ultimately trans...Mammalian spermatogenesis contains three continuous and organized processes, by which spermatogonia undergo mitosis and differentiate to spermatocytes, follow on meiosis to form haploid spermatids and ultimately transform into spermatozoa. These processes require an accurately, spatially and temporally regulated gene expression patterns. The microRNAs are a novel class of post-transcriptional regulators. Cumulating evidences have demonstrated that microRNAs are expressed in a cell-specific or stage-specific manner during spermatogenesis. In this review, we focus on the roles of microRNAs in spermatogenesis. We highlight that N6-methyladenosine(m6A)is involved in the biogenesis of microRNAs and miRNA regulates the m6A modification on mRNA, and that specific mi RNAs have been exploited as potential biomarkers for the male factor infertility, which will provide insightful understanding of microRNA roles in spermatogenesis.展开更多
基金supported by“National Key Research and Development Program of China”(Grant No.2021YFF1000701)“National Natural Science Foundation of China”(Grant No.U22A20509)。
文摘Background The cellular basis of testicular development and spermatogenesis for the extreme sperm density in chickens(100-fold higher than mammals)remains poorly defined.A comprehensive understanding of the molecular characteristics driving poultry testicular development is crucial for explaining this enhanced spermatogenic capacity.Results Here,we first established a single-cell transcriptome profile of chicken testes from hatching to maturity,identifying the dynamic transcriptional characteristics of germ cell fate transition and exploring the developmental characteristics of Sertoli cells and Leydig cells.Multi-species comparisons revealed a higher proportion of germ cells and the unique adaptations of Sertoli cells in chicken testes.Most importantly,our results demonstrated that Sertoli cells dominated in somatic composition of mature chicken testes,and proliferating Sertoli cells persisted in chicken testes even after sexual maturity,while no proliferating Sertoli cells in mammals.We also found a richer interaction network between chicken testicular cells,especially the specific activation of Sertoli cell interaction signals,such as TGF-β,BMP,EGF,and activin.These adaptations of Sertoli cells may support the spermatogenic superiority in chickens.Additionally,our results indicated that cAMP responsive element binding protein 5(CREB5)played a crucial role in maintaining the maturation and function of chicken Sertoli cells,and circadian rhythm promoted testosterone secretion and the development of Leydig cells.Conclusion Our study revealed that the sustained proliferative capacity of Sertoli cells,their enriched signaling network,and the regulatory roles of CREB5 and circadian rhythms collectively represented unique testicular adaptations in chickens.These findings may hold extraordinary significance in understanding the molecular characteristics of poultry testicular development,and provide a plausible framework for explaining enhanced spermatogenesis in poultry.
文摘As prepubertal boys do not yet produce spermatozoa,they cannot rely on sperm cryopreservation for fertility preservation before gonadotoxic therapy,such as high-dose alkylating agents or radiotherapy in the case of childhood cancers.According to the current guidelines,cryopreservation of testicular biopsies containing spermatogonial stem cells(SSCs)may be proposed to high-risk patients for potential later therapeutic use to fulfill the patients’wish for a biological child.One promising technique for human in vitro spermatogenesis and in vitro propagation of human SSCs is microfluidic(MF)culture,in which cells or tissues are subjected to a continuous flow of medium.This provides exact control over such parameters as nutrient content and gradients,as well as the removal of waste metabolites.While MF has been shown to maintain tissues and cell populations of organs for longer than conventional in vitro culture techniques,it has not been widely used for testicular in vitro culture.MF could advance human testicular in vitro culture and is also applicable to reprotoxicity studies.This review summarizes the findings and achievements of testis-on-chip(ToC)setups to date and discusses the benefits and limitations of these for spermatogenesis in vitro and toxicity assessment.
基金financially supported by the Shandong Provincial Natural Science Foundation(No.ZR2021QC182).
文摘Spermatogenesis is a fundamental process that requires a tightly controlled epigenetic event in spermatogonial stem cells(SSCs).The mechanisms underlying the transition from SSCs to sperm are largely unknown.Most studies utilize gene knockout mice to explain the mechanisms.However,the production of genetically engineered mice is costly and time-consuming.In this study,we presented a convenient research strategy using an RNA interference(RNAi)and testicular transplantation approach.Histone H3 lysine 9(H3K9)methylation was dynamically regulated during spermatogenesis.As Jumonji domain-containing protein 1A(JMJD1A)and Jumonji domain-containing protein 2C(JMJD2C)demethylases catalyze histone H3 lysine 9 dimethylation(H3K9me2),we firstly analyzed the expression profile of the two demethylases and then investigated their function.Using the convenient research strategy,we showed that normal spermatogenesis is disrupted due to the downregulated expression of both demethylases.These results suggest that this strategy might be a simple and alternative approach for analyzing spermatogenesis relative to the gene knockout mice strategy.
文摘Morphology of the male reproductive system, chromosome behaviors during meiosis and spem tail structures in Homoptera and Heteroptera are compared in this paper. The sheathed testis is found in Fulgoroidea and Heteroptera, and unsheathed testis occurs in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Psyloidea, Aphidoidea, Aleyrodoidea and Coccoidea. The testis also can be divide into three types by the shape of testicular follicles. The sphere-shaped type is found in Cicadoidea, Cicadelloidea, Cercopoidea, Membracoidea, Aphidoidea and Aleyrodoidea, the tube-shaped type observed in Fulgoroidea, Psyloidea and Coccoidea, and the lamella-shaped type represented by Heteroptera. It is suggested the unsheathed testis may be the primitive type in Homoptera. Meiosis can be divided into 6 type at least, i.e. 1） Cicadoid type; 2） Fulgoroid type; 3） Psyloid type; 4） Aphidoid type; 5） Aleyrodoid type; and 6） Coccoid type. At least four groups exhibit a diffuse stage during meiosis prophase l, they are Psyloidea, Fulgoroidea, Coccoidea and Heteroptera. Sperm tail structures are similar to those reported from other insects with a typical 9＋9＋2 axoneme except that in Aleyrodoidea and Coccoidea whose sperm tail is degenerated.
基金supported by the 10 KP project(https://db.cngb.org/1Okp/)and the Scientific Foundation of the Urban Management Bureau of Shenzhen(202403).
文摘Marchantia polymorpha,a model liverwort,provides a valuable system for investigating the evolution of plant sexual reproduction.To explore the cellular landscape of its reproductive structures,we generate a single-nucleus transcriptomic atlas of the antheridiophore,archegoniophore,and sporophyte.Using singlenucleus RNA sequencing(snRNA-seq),we capture over 30,000 high-quality nuclei and identify distinct cel populations.In the male organ,we characterize stages of spermatogenesis from early antheridium cells to mature sperm,revealing dynamic transcriptional programs including cell cycle regulation,chromatin remodeling,and calcium signaling.In the female organ,we define cell types including archegonial layers and secondary central cells.Sporophyte clusters are annotated as spores,elaters,capsule wall,foot,and seta cells,with transcriptional signatures related to structural support,stress response,and reproductive functions.Cross-species analysis indicates that capsule wall cells in liverworts are similar to tapetum cells.Notably,foot cells exhibit high expression of genes involved in sporopollenin biosynthesis and signaling pathways,serving as a central hub that mediates communication between the maternal gametophyte and the developing sporophyte.This study provides a comprehensive cellular and molecular map of M.polymorpha reproductive organs and sporophyte,establishing a framework for investigating the development and evolution of sexual reproduction in early land plants.
文摘目的采用文献计量学方法,分析2004年—2024年支持细胞在精子发生领域的研究热点和发展趋势。方法检索2004年—2024年Web of Science核心数据库、中国知网收录的支持细胞相关研究,共筛选出5679篇英文文献和455篇中文文献,采用CiteSpace软件对发文量、研究机构、作者合作网络及关键词进行系统性分析。结果英文关于支持细胞的研究发文量显著多于中文,且英文研究机构如Population Council在国际合作网络中处于核心地位,而中文研究机构的国际合作相对较少。英文作者在研究持续性、团队协作及发文量方面较有优势,而中文作者的研究多为短期或独立完成。关键词分析表明,英文研究主要聚焦于支持细胞的分子机制如基因表达、血睾屏障、精原干细胞等,而中文研究则更多关注传统动物模型及新兴领域如中药研究、铁死亡、信号通路等。结论基于文献计量分析结果,当前支持细胞在精子发生领域的研究中,英文文献在发文规模、合作网络、研究连续性及国际影响力上均显著占优,其研究已深入分子机制并整合多种前沿技术;中文研究则侧重于传统动物模型,并聚焦于中药干预与铁死亡等新兴方向。未来,中文研究需加强国际合作、稳定团队建设、系统阐释精子发生调控网络,并推动中药多靶点作用机制与现代生殖生物学的深度融合,以提升整体研究水平。
文摘To investigate the effect of arsenic on spermatogenesis. Methods: Mature (4 months old) Wistar rats were intraperitoneally administered sodium arsenite at doses of 4, 5 or 6 mg-kg^-day1 for 26 days. Different varieties of germ cells at stage VII seminiferous epithelium cycle, namely, type A spermatogonia (ASg), preleptotene spermatocytes (pLSc), midpachytene spermatocytes (mPSc) and step 7 spermatids (7Sd) were quantitatively evaluated, along with radioimmunoassay of plasma follicle-stimulating hormone (FSH), lutuneizing hormone (LH), testosterone and assessment of the epididymal sperm count. Results: In the 5 and 6 mg/kg groups, there were significant dose-dependent decreases in the accessory sex organ weights, epididymal sperm count and plasma concentrations of LH, FSH and testosterone with massive degeneration of all the germ cells at stage VII. The changes were insignificant in the 4 mg/kg group. Conclusion: Arsenite has a suppressive influence on spermatogenesis and gonadotrophin and testosterone release in rats.
文摘Spermatogenesis is a complex process regulated by endocrine and testicular paracrine/autocrine factors. Gonadotropins are involved in the regulation of several testicular paracrine factors, mainly of the IL-1 family and testicular hormones. Testicular cytokines and growth factors (such as IL-1, IL-6, TNF, IFN-γ, LIF and SCF) were shown to affect both the germ cell proliferation and the Leydig and Sertoli cells functions and secretion. Cytokines and growth factors are produced by immune cells and in the interstitial and seminiferous tubular compartments by various testicular cells, including Sertoli, Leydig, peritubular cells, spermatogonia, differentiated spermatogonia and even spermatozoa. Corresponding cytokine and growth factor receptors were demonstrated on some of the testicular cells. These cytokines also control the secretion of the gonadotropins and testosterone in the testis. Under pathological conditions the levels of pro-inflammatory cytokines are increased and negatively affected spermatogenesis. Thus, the expression levels and the mechanisms involved in the regulation of testicular paracrine/autocrine factors should be considered in future therapeutic strategies for male infertility.
基金Acknowledgment This work was supported by grants from National Natural Science Foundation of China （No. 30471729） and the ＂211＂ Project of the ＂Tenth-Five＂ Program for Peking University Health Science Center, China （No. 219）.
文摘Aim： To investigate the expression and subcellular localization of chemokine-like factor superfamily 2 （CKLFSF2） in human testis and its potential role in spermatogenesis. Methods： A specific polyclonal antibody against CKLFSF2 was raised. The expression and cellular localization of CKLFSF2 in the seminiferous tubules was checked by immunohistochemistry method. Also, in situ hybridization was applied to localize the mRNA distribution. The EGFP- CKLFSF2 fusion protein was expressed in COS-7 cells to localize its subcellular location in vitro. In addition, the abnormal expression of CKLFSF2 in testes of patients with male infertility was assayed by reverse transcription polymerase chain reaction （RT-PCR） and immunohistochemistry methods. Results： Having a close correlation with spermatogenesis defects, CKLFSF2 was specifically expressed in meiotic and post-meiotic germ cells, which were localized to the endoplasmic reticulum （ER） near the Golgi apparatus. Conclusion： CKLFSF2 could play important roles in the process of meiosis and spermiogenesis, and might be involved in the vesicular transport or membrane apposition events in the endoplasmic reticulum.
文摘The effects of diabetes mellitus include long-term damages, dysfunctions, and failures of various organs. An important complication of diabetes is the disturbance in the male reproductive system. Glucose metabolism is an important event in spermatogenesis. Moreover, glucose metabolism is also important for maintaining basic cell activity, as well as specific functions, such as motility and fertilization ability in mature sperm. Diabetic disease and experimentally induced diabetes both demonstrated that either type 1 diabetes or type 2 diabetes could have detrimental effects on male fertility, especially on sperm quality, such as sperm motility, sperm DNA integrity, and ingredients of seminal plasma. Epigenetic modifications are essential during spermatogenesis. The epigenetic regulation represents chromatin modifications including DNA methylation, histone modifications, remodeling of nucleosomes and the higher-order chromatin reorganization and noncoding RNAs. If spermatogenesis is affected during the critical developmental window, embryonic gonadal development, and germline differentiation, environmentally-induced epigenetic modifications may become permanent in the germ line epigenome and have a potential impact on subsequent generations through epigenetic transgenerational inheritance. Diabetes may influence the epigenetic modification during sperm spermatogenesis and that these epigenetic dysregulation may be inherited through the male germ line and passed onto more than one generation, which in turn may increase the risk of diabetes in offspring.
文摘Aim:To determine the effect of oral administration of an aqueous extract from the roots of Lepidium meyenii(maca)on spermatogenesis in adult male rats.Methods;Male rats received an aqueous extract of the root(66.7 mg in onemL)twice a day for 14 consecutive days.Results:Treatment with Lepidium meyenii resulted in an increase in theweights of testis and epididymis but not the seminal vesicle weight.The length and frequency of stages IX-XIV seminif-erous tubules,where mitosis occurred,were increased and stages I-VI were reduced in rats treated with Lepidiummeyenii.Conclusion;The Lepidium meyenii root invigorates spermatogenesis in male rats by acting on its initialstages(IX-XIV).
基金This work was supported by the National Basic Research Program （Nos. 2013CB947900, 2013CB945502 and 2014CB943101） of China （973）, by grants from National Natural Science Foundation of China （No. 31371519） and the Knowledge Innovation Program of the Chinese Academy of Sciences （No. KSCX2-EW-R-07）.
文摘The blood-testis barrier （BTB） is found between adjacent Sertoli cells in the testis where it creates a unique microenvironment for the development and maturation of meiotic and postmeiotic germ cells in seminiferous tubes. It is a compound proteinous structure, composed of several types of cell junctions including tight junctions （TJs）, adhesion junctions and gap junctions （GJs）. Some of the junctional proteins function as structural proteins of BTB and some have regulatory roles. The deletion or functional silencing of genes encoding these proteins may disrupt the BTB, which may cause immunological or other damages to meiotic and postmeiotic cells and ultimately lead to spermatogenic arrest and infertility. In this review, we will summarize the findings on the BTB structure and function from genetically-modified mouse models and discuss the future perspectives.
文摘We investigated whether letrozole （2.5 mg day-1） improves sperm count in non-obstructive azoospermia （NOA） patients. Four men were included in this study, and they had folliculo-stimulating hormone and other hormone levels within the normal range and no varicoceles or chromosomal aberrations. These four patients were administered letrozole for 3 months. Sperm count, testicular volume, gonadotropin, testosterone （T） and estradiol （E2） blood levels were assessed before, during and 1 week after the suspension of treatment. All patients showed spermatozoa in their ejaculate, increased gonadotropin and T levels and lower E2 levels （P〈0.05 in all cases）, when letrozole was administered. This suggests that letrozole treatment might improve sperm count in an NOA sub-population; however, more studies, including the proper controls, are needed to confirm its efficacy.
文摘Aim： To determine whether vasectomy away from the epididymal tail （via the inguinal canal） in rabbits can reduce the early postoperative effects on spermatogenesis. Methods： Twenty-nine normal male Japanese white rabbits （aged 4- 6 months） were subjected to unilateral close-ended （conventional） or open-ended （the cut end of the juxta-epididymal vas deferens not ligated） vasectomy via the inguinal canal. Ten days and 3 months after operation, testes, epididymides and vasa deferentia were removed and methacrylate resin-embedded sections prepared. The histology of the testis, epididymis and vas deferens was examined under light microscope, and the volume and diameter of the seminiferous tubules were quantitatively studied using stereological methods. Results： Neither of the methods of vasectomy led to apparent damage to spermatogenesis on the vasectomized side in comparison with the contralateral shamoperated side, but the juxta-epididymal vas deferens on the vasectomized side was highly distended and contained numerous sperm 3 months after operation. Conclusion： Vasectomy away from the cauda epididymis has no significant early postoperative effects on spermatogenesis in rabbits.
文摘Both pulsatile gonadotropin-releasing hormone （GnRH） infusion and combined gonadotropin therapy （human chorionic gonadotropin and human menopausal gonadotropin [HCG/HMG]） are effective to induce spermatogenesis in male patients with congenital hypogonadotropic hypogonadism （CH H）. However, evidence is lacking as to which treatment strategy is better. This retrospective cohort study included 202 patients with CHH： twenty had received pulsatile GnRH and 182 had received HCG/HMG. Patients had received therapy for at least 12 months. The total follow-up time was 15.6 ± 5.0 months （range： 12-27 months） for the GnRH group and 28.7 ± 13.0 months （range： 12-66 months） for the HCG/HMG group. The median time to first sperm appearance was 6 months （95% confidence interval [CI]： 1.6-10.4） in the GnRH group versus 18 months （95% Ch 16.4-20.0） in the HCG/HMG group （P〈 0.001）. The median time to achieve sperm concentrations 〉5 x 106 m1-1 was 14 months （95% Ch 5.8-22.2） in the GnRH group versus 27 months （95% Ch 18.9-35.1） in the HCG/HMG group （P 〈 0.001）, and the median time to concentrations 〉10 x 106 m1-1 was 18 months （95% Ch 10.0-26.0） in the GnRH group versus 39 months （95% CI unknown） in the HCG/HMG group. Compared to the GnRH group, the HCG/HMG group required longer treatment periods to achieve testicular sizes of 〉4 ml, 〉8 ml, 〉12 ml, and 〉16 ml. Sperm motility （a ＋ b ＋ c percentage） evaluated in semen samples with concentrations 〉1 × 106 ml-1 was 43.7% ± 20.4% （16 samples） in the GnRH group versus 43.2% ± 18.1% （153 samples） in the HCG/HMG group （P= 0.921）. Notably, during follow-up, the GnRH group had lower serum testosterone levels than the HCG/HMG group （8.3 ±4.6 vs 16.2 ± 8.2 nmol 1-1, P 〈 0.001）. Our study found that pulsatile GnRH therapy was associated with earlier spermatogenesis and larger testicular size compared to combined gonadotropin therapy. Additional prospective randomized studies would be required to confirm these findings.
基金This work was supported by the National Natural Science Foundation of China （Number 31371174）, the Natural Science Foundation of Jiangsu Province, China （Number BK20131230）, and the Postgraduate Research and Practice Innovation Program of Jiangsu Province, China （KYCX17-1893）. We thank Dr. Wilkinson （University of California, USA） for kindly providing Rhox 10 antibody.
文摘To clarify the functions and mechanism of stimulated by retinoic acid gene 8 （Stra8） in spermatogenesis, we analyzed the testes from Stra8 knockout and wild-type mice during the first wave of spermatogenesis. Comparisons showed no significant differences in morphology and number of germ cells at 11 days postpartum, while 21 differentially expressed genes （DEGs） associated with spermatogenesis were identified. We speculate that Stra8 performs many functions in different phases of spermatogenesis, such as establishment of spermatogonial stem cells, spermatogonial proliferation and self-renewal, spermatogonial differentiation and meiosis, through direct or indirect regulation of these DEGs. We therefore established a preliminary regulatory network of Stra8 during spermatogenesis. These results will provide a theoretical basis for further research on the mechanism underlying the role of Stra8 in spermatogenesis.
基金funded,in part,by the National Basic Research Program of China(973 programNo.2013CB943103)+1 种基金the National Natural Science Foundation of China(No.31272439,No.31230048 and No.31572401)Programs Foundation of Ministry of Education of China(No.20130204110017)
文摘Mammalian spermatogenesis contains three continuous and organized processes, by which spermatogonia undergo mitosis and differentiate to spermatocytes, follow on meiosis to form haploid spermatids and ultimately transform into spermatozoa. These processes require an accurately, spatially and temporally regulated gene expression patterns. The microRNAs are a novel class of post-transcriptional regulators. Cumulating evidences have demonstrated that microRNAs are expressed in a cell-specific or stage-specific manner during spermatogenesis. In this review, we focus on the roles of microRNAs in spermatogenesis. We highlight that N6-methyladenosine(m6A)is involved in the biogenesis of microRNAs and miRNA regulates the m6A modification on mRNA, and that specific mi RNAs have been exploited as potential biomarkers for the male factor infertility, which will provide insightful understanding of microRNA roles in spermatogenesis.
