Meiotic abnormalities in metaphase I human spermatocytes from infertile males： frequencies, chromosomes involved, and relationship with polymorphic karyotype and seminal parameters

The aim of this study was to look in depth at the relationship between meiotic anomalies and male infertility, such as the determination of the chromosomes involved or the correlation with patient features. For this purpose, a total of 31 testicular tissue samples from individuals consulting for fertility problems were analyzed. Metaphase I cells were evaluated using a sequential methodology combining Leishman stained procedures and multiplex fluorescence in situ hybridization protocols. The number of chromosomal units and chiasmata count per bivalent were established and a hierarchical cluster analysis of the individuals was performed. The relationship of the seminogram and the karyotype over recombination were evaluated using Poisson regression models. Results obtained in this study show a significant percentage of infertile individuals with altered meiotic behavior, mostly specified as a reduction in chiasmata count in medium and large chromosomes, the presence of univalents, and the observation of tetraploid metaphases. Moreover, the number and the type of anomalies were found to be different between cells of the same individual, suggesting the coexistence of cell lines with normal meiotic behavior and cell lines with abnormalities. In addition, chromosomal abnormalities in metaphase I are significantly associated with oligozoospermia and/or polymorphic karyotype variants.

Melatonin relieves heat-induced spermatocyte apoptosis in mouse testes by inhibition of ATF6 and PERK signaling pathways

Normal spermatogenic processes require the scrotal temperature to be lower than that of the body as excessive heat affects spermatogenesis in the testes,reduces sperm quality and quantity,and even causes infertility.Endoplasmic reticulum stress(ERS)is a crucial factor in many pathologies.Although several studies have linked ERS to heat stress,researchers have not yet determined which ERS signaling pathways contribute to heat-induced testicular damage.Melatonin activates antioxidant enzymes,scavenges free radicals,and protects the testes from inflammation;however,few studies have reported on the influence of melatonin on heat-induced testicular damage.Using a murine model of testicular hyperthermia,we observed that heat stress causes both ERS and apoptosis in the testes,especially in the spermatocytes.These observations were confirmed using the mouse spermatocyte cell line GC2,where the Atf6 and Perk signaling pathways were activated during heat stress.Knockout of the above genes effectively reduced spermatocyte damage caused by heat stress.Pretreatment with melatonin alleviated heat-induced apoptosis by inhibiting the Atf6 and Perk signaling pathways.This mitigation was dependent on the melatonin receptors.In vivo experiments verified that melatonin treatment relieved heat-induced testicular damage.In conclusion,our results demonstrated that ATF6 and PERK are important mediators for heat-induced apoptosis,which can be prevented by melatonin treatment.Thus,our study highlights melatonin as a potential therapeutic agent in mammals for subfertility/infertility induced by testicular hyperthermia.

Cigarette smoke-induced cell cycle arrest in spermatocytes [GC-2spd(ts)] is mediated through crosstalk between Ahr–Nrf2 pathway and MAPK signaling

Our earlier studies have demonstrated that the cigarette smoke in the form of cigarette smoke condensate(CSC)causes growth arrest of a mouse spermatocyte cell line[GC-2spd(ts)]through activation of the AHR–NRF2 pathway.The present study demonstrates the CSC-activated p38 and ERK MAPK signaling in GC-2spd(ts)via arylhydrocarbon receptor(AHR).Pharmacological inhibition by using AHR-antagonist,or p38 MAPK and ERK(MEK1)inhibitors significantly abrogates CSC-induced growth arrest by AHR and MAPK inactivation.QRT-PCR,western blot,and immunofluorescence of Ahr-target of Nrf2,and stress-inducible growth suppressive Atf3 and E2f4 following treatments indicate a crosstalk among these pathways.Regulation of Atf3 by Nrf2 and Ahr through RNA interference suggests the existence of a cross-regulatory loop between the targets.CSC induction of E2f4 via Atf3 and its regulation by pharmacological inhibitors reveal a possible regulatory mechanism of growth inhibitory CSC.SiRNA silencing of Ahr,Nrf2,Atf3,and E2f4 genes and downregulation of cyclins by CSC corroborate the growth inhibitory effect of cigarette smoke.Thus,the data obtained suggest that the CSC-mediated MAPKs and AHR–NRF2 crosstalks lay the molecular basis for the growth arrest and cell death of spermatocytes.

Subzonal insemination with primary spermatocytes in mouse

IT is well known that oocytes, in general condition, can be penetrated by sperm rather thanround spermatids. In 1993, Ogura injected round spermatid nuclei into hamster oocytes anddemonstrated that the spermatid nuclei could transform into pronuclei with DNA synthesis andthat their chromosomes mingled with oocyte chromosomes immediately. In order to avoid themechanical damage to the oocytes, an alternative method, cell-to-cell fusion, was used. Ap-proximately 20%—40% and 30% of round spermatids could be fused with oocytes by

Expression of toxin-related human mono-ADP-ribosyltransferase 3 in human testes

Aim： To investigate wether the corresponding protein of mono-ADP-ribosyltransferase 3 （ART3） mRNA is expressed in human testes and, if so, whether the expression is cell type-specific. Methods： ART3 mRNA was determined in human testes and sperm by reverse transcription-polymerase chain reaction （RT-PCR）. The glycosylphosphatidylinositol linkage of ART3 was shown by treating ART3-transfected HEK-293-T cells with phospholipase C. Fluorescent activated cell sorter （FACS）-analyses were used to detect ART3 on mature spermatozoa and immunohistological studies to detect the protein in testes. Results： ART3 protein was shown to be present in testes. It was found on spermatocytes only. It was absent from spermatogonia, spermatids and spermatozoa. The absence of ART3 from spermatozoa was confirmed by FACS-analysis. ART3 protein was detected neither within a seminoma nor on Leydig cells. Conclusion： Here we show for the first time that ART3 protein is expressed in testes in particular on spermatocytes, indicating that ART3 exerts a specific function only required at a particular stage of spermatogenesis.

Effect of Semecarpus anacardium fruits on reproductive function of male albino rats

<abstract>Aim: To evaluate the effect of an ethanolic extract of Semecarpus anacardium fruits on spermatogenesis in albino rats. Methods: Male albino rats were fed with a 50 % ethanolic extract of Semecarpus anacardium fruit at 100 mg·kg-1.day-1, 200 mg·kg-1·day-1 and 300 mg·kg-1·day-1 for 60 days. Fertility test was performed after 60 days of treatment. Sperm motility and density were observed in the cauda epididymis. Biochemical and histological analyses of the blood and reproductive organs were done. Recovery of fertility was followed to evaluate the reversibility of drug action. Results: S. anacardium fruit extract administration resulted in spermatogenic arrest in albino rats. The sperm motility and density was reduced significantly. The RBC and WBC counts, haemoglobin, haematocrit, blood sugar and urea were found to be within the normal range in the whole blood. The protein, cholesterol and glycogen in the testes and the fructose in the seminal vesicle were significantly decreased after the treatment. The fruit extract feeding caused marked reduction in the number of primary spermatocytes, secondary spermatocytes and spermatids. The number of mature Leydig cells was also decreased and degenerating cells increased proportionately. Conclusion: 5. anacardium fruit extract causes spermatogenic arrest in albino rats.

Antifertility effects of methanolic pod extract of Albizzia lebbeck (L.) Benth in male rats

Aim: To evaluate the antifertility activity of the methanolic pod extract of Albizzia lebbeck (L.) Benth in male albino rats. Methods: The methanolic pod extract of Albizzia lebbeck was administrated orally for 60 days at 50, 100 and 200 mg·kg-1·day-1 to male albino rats. Sperm motility and density in cauda epididymides were assessed. Biochemical and histological analysis were performed in blood samples and reproductive organs. Results: A. lebbeck pod extract brought about a significant decrease in the weights of testis, seminal vesicles, epdidymis and ventral prostate. The sperm motility and density were significantly reduced. There was a marked reduction in the numbers of primary spermatocytes, secondary spermatocytes and spermatids. The Sertoli cell count as well as its cross sectional surface area were significantly decreased. The Leydig cell nuclear area and the number of mature Leydig celis were also significantly decreased. The protein, glycogen and cholesterol content of the testis, the fructose in the seminal vesicles and protein in the epididymis were significantly decreased. The RBC and WBC counts, haemoglobin, haematocrit and blood sugar were within the normai range. Conclusion: The methanolic extract of A. lebbeck pods causes spermatogenic arrest in male albino rats.

Long noncoding RNAs:new insights in modulating mammalian spermatogenesis

Spermatogenesis is a complex differentiating developmental process in which undifferentiated spermatogonial germ cells differentiate into spermatocytes,spermatids,and finally,to mature spermatozoa.This multistage developmental process of spermatogenesis involves the expression of many male germ cell-specific long noncoding RNAs(lncRNAs)and highly regulated and specific gene expression.LncRNAs are a recently discovered large class of noncoding cellular transcripts that are still relatively unexplored.Only a few of them have postmeiotic;however,lncRNAs are involved in many cellular biological processes.The expression of lncRNAs is biologically relevant in the highly dynamic and complex program of spermatogenesis and has become a research focus in recent genome studies.This review considers the important roles and novel regulatory functions whereby lncRNAs modulate mammalian spermatogenesis.

Differential Genotoxicity of the Crude Leaf Extract of a Medicinal Plant, Casearia tomentosa

The genotoxic potentiality of the crude leaf extract of Casearia tomentosa, a medicinal preparation, has been evaluated in Swiss albino mice. The extract significantly induced the division_disruptive chromosomal changes in bone marrow cells as well as in primary spermatocytes; the latter also exhibited marked increase in synaptic disruptions. A significant decrease in sperm count was noted. The incidence of structural damages in chromosomes, however, remained within the range of control level frequency. This herbal preparation, therefore, appears to be primarily spindle_poisoning in its action, but not clastogenic. The probable mechanism of this differential genotoxicity is discussed.

Spermatocytic tumor:A rare case report

BACKGROUND Spermatocytic tumor is a rare,malignant neoplasm of the testes.Since the prognosis for this tumor type is favorable,accurate diagnosis and differentiation from other malignant testicular neoplasms(classic seminoma and lymphoma)are crucial.To add to the existing literature on the diagnosis of spermatocytic tumor,herein we report the detailed clinical and histopathologic findings for a case that we encountered.CASE SUMMARY A 60-year-old Chinese man presented with a solid mass in the right scrotum.The mass was surgically removed and spermatocytic tumor was diagnosed.On microscopy,the tumor cells displayed an unusual arrangement in lobules,presenting a pseudo-glandular appearance.To summarize and compare the diagnostic features of this tumor and those of the differential diagnoses,we report our case findings and those mentioned in the literature for various testicular tumors.Although imaging methods can detect masses early in development,their diagnostic capabilities are limited.Biopsy,histopathology,and immunohistochemistry are necessary for confirmatory diagnosis.CONCLUSION It is important to identify and review the key diagnostic features of spermatocytic tumor.

Putting things in place for fertilization： discovering roles for importin proteins in cell fate and spermatogenesis

Importin proteins were originally characterized for their central role in protein transport through the nuclear pores, the only intracellular entry to the nucleus. This vital function must be tightly regulated to control access by transcription factors and other nuclear proteins to genomic DNA, to achieve appropriate modulation of cellular behaviors affecting cell fate. Importin-mediated nucleocytoplasmic transport relies on their specific recognition of cargoes, with each importin binding to distinct and overlapping protein subsets. Knowledge of importin function has expanded substantially in regard to three key developmental systems： embryonic stem cells, muscle cells and the germ line. In the decade since the potential for regulated nucleocytoplasmic transport to contribute to spermatogenesis was proposed, we and others have shown that the importins that ferry transcription factors into the nucleus perform additional roles, which control cell fate. This review presents key findings from studies of mammalian spermatogenesis that reveal potential new pathways by which male fertility and infertility arise. These studies of germline genesis illuminate new ways in which importin proteins govern cellular differentiation, includ ng v a d rect ng proteins to d st nct ntrace ular compartments and by determining cellular stress responses.

Melatonin alleviates heat stress‑induced testicular damage in dairy goats by inhibiting the PI3K/AKT signaling pathway

Current measures mainly focus on how melatonin reduces physiological heat stress in animals,but its effects on reproductive damage to male dairy goats have been neglected.This study aimed to determine the protective effect of melatonin on male reproduction during heat stress in dairy goats and to further explore its mechanisms.A natural heat stress model of Saanen dairy goats was used to assess testicular tissue damage 7days after heat stress and to examine semen quality changes during a spermatogenic cycle.RNA-seq,Western blot,RT–qPCR,and immunofluo-rescence staining were used to explore the mechanism by which melatonin protects against heat stress-induced reproductive damage and to validate the results.The data suggested that melatonin significantly alleviated the heat stress-induced decrease in sperm quality,protected varicose tubule structure,reduced the levels of heat shock proteins and apoptotic proteins and protected the spermatocytes and round spermatozoa,which are mainly affected by heat stress.RNA-seq results suggest that melatonin inhibits the PI3K/AKT signaling pathway,reduces the level of p-AKT,and promotes elevated BCL-2.In addition,melatonin treatment could upregulate the gene expression of MT2 which was downregulated by heat stress and improve the change in extracellular matrix components and restore serum testosterone levels.Our results suggest that melatonin can protect against testicular and spermatogenic cell damage and improve semen quality in male dairy goats under heat stress.This study provides an important reference for subsequent studies on the molecular mechanisms of melatonin in protecting male reproductive processes under heat stress and using exogenous melatonin to prevent heat stress.