The mutation features and geographical distributions of the surface glycoprotein (S gene) in SARS-CoV-2 strains: A comparative analysis of the early and current strains.

The surface glycoprotein (S protein) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was used to develop coronavirus disease 2019 (COVID-19) vaccines. However, SARS-CoV-2, especially the S protein, has undergone rapid evolution and mutation, which has remained to be determined. Here, we analyzed and compared the early (12 237) and the current (more than 10 million) SARS-CoV-2 strains to identify the mutation features and geographical distribution of the S gene and S protein. Results showed that in the early strains, most of the loci were with relative low mutation frequency except S: 23403 (4486 strains), while in the current strains, there was a surge in the mutation strains and frequency, with S: 23403 constantly being the highest one, but tremendously increased to approximately 1050 times. Furthermore, D614 (S: 23403) was one of the most highly frequent mutations in the S protein of Omicron as of March 2022, and most of the mutant strains were still from the United States, and the United Kingdom. Further analysis demonstrated that in the receptor-binding domain, most of the loci with low mutation frequency in the early strains, while S: 22995 was nowadays the most prevalent loci with 3 122 491 strains in the current strains. Overall, we compare the mutation features of the S region in SARS-CoV-2 strains between the early and the current stains, providing insight into further studies in concert with emerging SARS-CoV-2 variants for COVID-19 vaccines.

Three-Dimensional Genome Interactions Identify Potential Adipocyte Metabolism-Associated Gene STON1 and Immune-Correlated Gene FSHR at the rs13405728 Locus in Polycystic Ovary Syndrome.

Background: rs13405728 was identified as one of the most prevalent susceptibility loci for polycystic ovary syndrome (PCOS) in Han Chinese and Caucasian women. However, the target genes and potential mechanisms of the rs13405728 locus remain to be determined. Methods: Three-dimensional (3D) genome interactions from the ovary tissue were characterized via high-through chromosome conformation capture (Hi-C) and Capture Hi-C technologies to identify putative targets at the rs13405728 locus. Combined analyses of eQTL, RNA-Seq, DNase-Seq, ChIP-Seq, and sing-cell sequencing were performed to explore the molecular roles of these target genes in PCOS. PCOS-like mice were applied to verify the expression patterns. Results: Generally, STON1 and FSHR were identified as potential targets of the rs13405728 locus in 3D genomic interactions with epigenomic regulatory peaks, with STON1 (P=0.0423) and FSHR (P=0.0013) being highly expressed in PCOS patients. STON1 co-expressed genes were associated with metabolic processes (P=0.0008) in adipocytes (P=0.0001), which was validated in the fat tissue (P<0.0001) and ovary (P=0.0035) from fat-diet mice. The immune system process (GO:0002376) was enriched in FSHR co-expressed genes (P=0.0002) and PCOS patients (P=0.0002), with CD4 high expression in PCOS patients (P=0.0316) and PCOS-like models (P=0.0079). Meanwhile, FSHR expression was positively correlated with CD4 expression in PCOS patients (P=0.0252) and PCOS-like models (P=0.0178). Furthermore, androgen receptor (AR) was identified as the common transcription factor for STON1 and FSHR and positively correlated with the expression of STON1 (P=0.039) and FSHR (P=4e-06) in ovary tissues and PCOS-like mice. Conclusion: Overall, we identified STON1 and FSHR as potential targets for the rs13405728 locus and their roles in the processes of adipocyte metabolism and CD4 immune expression in PCOS, which provides 3D genomic insight into the pathogenesis of PCOS.

LRP1B mutation is associated with tumor HPV status and promotes poor disease outcomes with a higher mutation count in HPV-related cervical carcinoma and head & neck squamous cell carcinoma.

Human papillomavirus (HPV) infection and gene mutations were reputed as key factors in cervical carcinoma (CC) and head and neck squamous cell carcinoma (HNSCC). However, the associations of HPV status and gene mutations remain to be determined. This study aims to identify molecular patterns of LRP1B mutation and HPV status via rewiring tumor samples of HNSCC (n=1478) and CC (n=178) from the TCGA dataset. Here, we found that LRP1B mutation was associated with HPV status in CC (P=0.040) and HNSCC (P=0.044), especially in HPV 16 integrated CC (P=0.036). Cancer survival analysis demonstrated that samples with LRP1B mutation showed poor disease outcomes in CC (P=0.013) and HNSCC (P=0.0124). In addition, the expression status of LPR1B was more favorable for prediction than TP53 or RB1 in CC and HNSCC. Mutation clustering analysis showed that samples with LRP1B mutation showed higher mutation count in CC (P=1.76e-67) and HNSCC (P<10e-10). Further analysis identified 289 co-occurrence genes in these two cancer types, which were enriched in PI3K signaling, cell division process, and chromosome segregation process, et al. The 289-co-occurrence gene signature identified a cluster of patients with a higher portion of copy number variation (CNV) lost in the genome, different tumor HPV status (P<10e-10), higher mutation count (P<10e-10), higher fraction genome altered value (P=2.078e-4), higher aneuploidy score (P=3.362e-4), and earlier started the smoking year (P=2.572e-4), which were associated with shorter overall survival (P=0.0103) in CC and HNSCC samples. Overall, LRP1B mutation was associated with tumor HPV status and was an unfavorable prognostic biomarker for CC and HNSCC.

Alterations in Vaginal Microbiota and Associated Metabolome in Women with Recurrent Implantation Failure.

Recurrent implantation failure (RIF) refers to repeated failure to become pregnant after transferring embryos with normal morphology. However, the pathogenesis of RIF remains unrevealed, especially for those without any pathological features. In this study, we characterized the vaginal microbiota and metabolomes of patients with unexplained RIF, while patients who achieved clinical pregnancy in the first frozen embryo transfer (FET) cycle were used as controls. Based on 16S rRNA gene sequencing of the vaginal microbiota, the vaginal Lactobacillus showed a significant positive correlation with the pregnancy rate, and the RIF group presented higher microbial α-diversity than the control group (P value = 0.016). The metabolomic profile identified 2,507 metabolites, of which 37 were significantly different between the two groups (P value < 0.05, variable importance for the projection [VIP] > 1). Among them, 2',3-cyclic UMP and inositol phosphate were the top two metabolites that were higher in the RIF group, while glycerophospholipids and benzopyran were important metabolites that were lower in the RIF group. A lack of lysobisphosphatidic acid and prostaglandin metabolized from glycerophospholipids will lead to deferred implantation and embryo crowding. Benzopyran, as a selective estrogen receptor modulator, may affect the outcome of pregnancy. All of the changes in metabolite profiles may result in or from the differential microbiota compositions in RIF patients. In conclusion, significant differences were presented in the vaginal microbiota and metabolomes between patients with unexplained RIF and women who became pregnant in the first FET cycle. For the first time, this study elaborates the possible pathogenesis of RIF by investigating the vaginal microbiota and metabolites in RIF patients.IMPORTANCEIn vitro fertilization-embryo transfer (IVF-ET) is now widely applied for treating infertility, and unexplained recurrent implantation failure (RIF) has become a substantial challenge. We hypothesize that vaginal microbial dysbiosis is associated with RIF, as it is linked to many female reproductive diseases. In this study, we characterized the vaginal microbiota and metabolomes of patients with unexplained RIF, while patients who achieved clinical pregnancy in the first IVF cycle were set as controls. In general, significant differences were discovered in the vaginal microbiota and metabolomes between the two groups. This study is the first detailed elaboration of the vaginal microbiota and metabolites associated with RIF. We believe that our findings will inspire researchers to consider the dynamics of microbiomes related to the microenvironment as a critical feature for future studies of nosogenesis not only for RIF but also for other reproductive diseases.

Systematic analysis of survival-associated alternative splicing signatures in clear cell renal cell carcinoma.

Alternative splicing (AS) constitutes a major reason for messenger RNA (mRNA) and protein diversity. Increasing studies have shown a link to splicing dysfunction associated with malignant neoplasia. Systematic analysis of AS events in kidney cancer remains poorly reported. Therefore, we generated AS profiles in 533 kidney renal clear cell carcinoma (KIRC) patients in The Cancer Genome Atlas (TCGA) database using RNA-seq data. Then, prognostic models were developed in a primary cohort (N = 351) and validated in a validation cohort (N = 182). In addition, splicing networks were built by integrating bioinformatics analyses. A total of 11 268 and 8083 AS variants were significantly associated with patient overall survival time in the primary and validation KIRC cohorts, respectively, including STAT1, DAZAP1, IDS, NUDT7, and KLHDC4. The AS events in the primary KIRC cohorts served as candidate AS events to screen the independent risk factors associated with survival in the primary cohort and to develop prognostic models. The area under the curve of the receiver-operator characteristic curve for prognostic prediction in the primary and validation KIRC cohorts was 0.84 and 0.82 at 2500 days of overall survival, respectively. In addition, splicing correlation networks revealed key splicing factors (SFs) in KIRC, such as HNRNPH1, HNRNPU, KHDBS1, KHDBS3, SRSF9, RBMX, SFQ, SRP54, HNRNPA0, and SRSF6. In this study, we analyzed the AS landscape in the TCGA KIRC cohort and detected predictors (prognostic) based on AS variants with high performance for risk stratification of the KIRC cohort and revealed key SFs in splicing networks, which could act as underlying mechanisms.

Identification and functional analysis of spermatogenesis-associated gene modules in azoospermia by weighted gene coexpression network analysis.

Nonobstructive azoospermia (NOA) or testicular failure is the most severe form of male infertility. A variety of conditions, both acquired and congenital, can cause azoospermia. However, in a large number of azoospermia patients who are classified as idiopathic cases, the etiology remains poorly understand mainly due to the lack of knowledge of all the genetic causes and molecular mechanisms responsible for spermatogenesis failure. Identification of the key gene modules and pathways-related spermatogenesis failure might help to reveal the mechanisms of idiopathic azoospermia. Therefore, the expression patterns of spermatogenesis-associated genes in NOA were analyzed by weighted gene coexpression network analysis (WGCNA) based on two public microarray data sets (GSE45885 and GSE45887), which included 51 samples and 32,321 genes. We identified a module (turquoise) that was significantly related to the Johnsen score of the testicular samples. In addition, the results of function and pathway enrichment analyses based on the online bioinformatics database Metascape revealed that genes in the turquoise module were mainly related to the process of spermatogenesis and spermatid development. To further identify spermatogenesis-associated genes, a microarray data set (GSE926) of murine testis at different developmental time points was analyzed by WGCNA. The blue module in GSE926 was significantly related to the time of murine testis development. The overlap study and k-core analysis based on protein-protein interaction network revealed that spermatogenesis- and spermatid development-associated genes, including glyceraldehyde-3-phosphate dehydrogenase, ADAM metallopeptidase domain 2, transition protein 1, testis-specific serine kinase 2, transition protein 2, and germ cell-associated 1 (GSG1), were further identified in the selected modules. The expression profile of GSG1 in human testis was chosen for further study using immunochemistry staining. Taken together, these screened gene modules and pathways provided a more detailed genetic and molecular mechanism underlying spermatogenesis failure occurrence and holds promise as potential diagnosis biomarkers and therapeutic targets.

The expression characteristics of FAM71D and its association with sperm motility.

STUDY QUESTION: What are the features of FAM71D (Family with sequence similarity 71, member D) expression and is there an association between FAM71D expression and sperm motility? SUMMARY ANSWER: FAM71D, a novel protein exclusively expressed in the testis, is located in sperm flagella and is functionally involved in sperm motility. WHAT IS KNOWN ALREADY: Some testis-specific proteins have been reported as potential diagnostic biomarkers to evaluate the spermatogenesis process and sperm quality. We have identified a novel testis-specific protein, FAM71D, through microarray data analysis, yet little is known about its expression and function. STUDY DESIGN, SIZE, DURATION: FAM71D mRNA and protein expression was quantified during mouse testis development. Its localization in germ cells was detected by dual-labeled immunostaining in testis sections and sperm smears. The clinical significance was assessed by comparing FAM71D expression in spermatozoa from normozoospermic controls and asthenozoospermic patients. PARTICIPANTS/MATERIALS, SETTING, METHODS: Testes were dissected from C57BL/6 J male mice at postnatal ages of 1, 2, 3, 4, 6, 8 weeks and 6 months, and sperm was collected from cauda epididymides of adult mice by the swim-up method. Human spermatozoa were isolated from 100 human semen samples by density gradient Percoll centrifugation. RT-qPCR and western blot were performed to semi-quantify the expression of FAM71D in mouse testis, and in the ejaculated spermatozoa of normozoospermic controls and asthenozoospermic patients. Immunofluorescence staining was used to detect the localization of FAM71D. Co-immunoprecipitation assay was performed to evaluate the interaction between FAM71D and calmodulin. An antibody blocking assay was employed to assess the role of FAM71D in sperm motility. MAIN RESULTS AND THE ROLE OF CHANCE: Our results showed that FAM71D was exclusively expressed in the testis in an age-dependent manner. FAM71D expression exhibited dynamic change in the cytoplasm of spermatids during spermiogenesis and was finally retained in sperm flagella. FAM71D could interact with calmodulin. Use of anti-FAM71D antibody on sperm significantly decreased sperm motility. Expression level of FAM71D was markedly reduced in the ejaculated spermataozoa of asthenozoospermic patients (P < 0.05), and this was correlated with sperm progressive motility (r = 0.7435, P < 0.0001). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: The sample size was limited and it is necessary to verify the correlation of FAM71D expression with sperm motility in larger cohorts. Furthermore, our results were descriptive and follow-up studies would be needed to elucidate the detailed role of FAM71D in sperm motility. WIDER IMPLICATIONS OF THE FINDINGS: This is the first systematic study to document the expression of endogenous FAM71D and a function for FAM71D in sperm motility. It provides new insights into our understanding of sperm motility regulation and causes of male infertility. STUDY FUNDING/COMPETING INTERESTS: This study was funded by the National Natural Science Foundation of China, Guangdong Natural Science Foundation and the Shenzhen Project of Science and Technology. The authors have no competing interests.

Comparisons of GnRH antagonist protocol versus GnRH agonist long protocol in patients with normal ovarian reserve: A systematic review and meta-analysis.

OBJECTIVE: To evaluate the effectiveness and safety of gonadotropin-releasing hormone antagonist (GnRH-ant) protocol and gonadotropin-releasing hormone agonist (GnRH-a) long protocol in patients with normal ovarian reserve. METHODS: We searched the PubMed (1992-2016), Cochrane Library (1999-2016), Web of Science (1950-2016), Chinese Biomedical Database (CBM, 1979-2016), and China National Knowledge Infrastructure (CNKI, 1994-2016). Any randomized controlled trials (RCTs) that compared GnRH-ant protocol and GnRH-a long protocol in patients with normal ovarian reserve were included, and data were extracted independently by two reviewers. The meta-analysis was performed by Revman 5.3 software. RESULTS: Twenty-nine RCTs (6399 patients) were included in this meta-analysis. Stimulation days (mean difference (MD) [95% confidence interval (CI)] = -0.8 [-1.36, -0.23], P = 0.006), gonadotrophin (Gn) dosage (MD [95% CI] = -3.52 [-5.56, -1.48], P = 0.0007), estradiol (E2) level on the day of human chorionic gonadotrophin (HCG) administration (MD [95% CI] = -365.49 [-532.93, -198.05], P<0.0001), the number of oocytes retrieved (MD [95% CI] = -1.41 [-1.84, -0.99], P<0.00001), the embryos obtained (MD [95% CI] = -0.99 [-1.38, -0.59], P<0.00001), incidence of ovarian hyperstimulation syndrome (OHSS) (OR [95% CI] = 0.69 [0.57, 0.83], P<0.0001) were statistically significantly lower in GnRH-ant protocol than GnRH-a long protocol. However, the clinical pregnancy rate (OR [95% CI] = 0.90 [0.80, 1.01], P = 0.08), ongoing pregnancy rate (OR [95% CI] = 0.88 [0.77, 1.00], P = 0.05), live birth rate (OR [95% CI] = 0.95 [0.74, 1.09], P = 0.27), miscarriage rate (OR [95% CI] = 0.98 [0.69, 1.40], P = 0.93), and cycle cancellation rate (OR [95% CI] = 0.86 [0.52, 1.44], P = 0.57) showed no significant differences between the two groups. CONCLUSION: GnRH-ant protocol substantially decreased the incidence of OHSS without influencing the pregnancy rate and live birth rate compared to GnRH-a long protocol among patients with normal ovarian reserve.

A nonsense mutation in Ccdc62 gene is responsible for spermiogenesis defects and male infertility in repro29/repro29 mice.

Phenotype-driven mutagenesis is an unbiased method to identify novel genes involved in spermatogenesis and other reproductive processes. Male repro29/repro29 mice generated by the Reproductive Genomics Program at the Jackson Laboratory were infertile with deformed sperm and poor motility. Using selected exonic capture and massively parallel sequencing technologies, we identified a nonsense mutation in the exon 6 of coiled-coil domain-containing 62 gene (Ccdc62), which results in a formation of a premature stop codon and a truncated protein. Among the tissues examined, CCDC62 was found to be expressed at the highest level in mouse testis by reverse transcriptase-PCR (RT-PCR) and Western blot analysis. With immunofluorescent staining, we demonstrated that CCDC62 was expressed in the cytoplasm and the developing acrosome in the spematids of mouse testis, and was specifically localized at the acrosome in mature sperm. The complementation analysis by mating repro29/+ mice with Ccdc62 -/- mice (generated by CRISPR-Cas9 strategy) further provided genetic proof that the infertility of repro29/repro29 mice was caused by Ccdc62 mutation. Finally, it was found that intracellular colocalization and interaction of CCDC62 and Golgi-associated PDZ and coiled-coil motif-containing protein may be important for acrosome formation. Taken together, this study identified a nonsense mutation in Ccdc62, which directly results in male infertility in repro29/repro29 mice.

Deficiency of SPATA46, a Novel Nuclear Membrane Protein, Causes Subfertility in Male Mice.

Teratozoospermia is generally associated with clinical infertility. Despite numerous studies, the molecular mechanisms underlying male infertility are still poorly understood. In the present study, we demonstrated that deletion of Spata46, a gene encoding a novel protein of unknown function found in mouse testis, was responsible for male subfertility, and the cause of subfertility was characterized as abnormal sperm head shape and a failure of sperm-egg fusion. We also demonstrated that SPATA46 was expressed predominantly in condensed spermatids, with a highly specific localization restricted to the subacrosomal area; the protein is located at the nuclear membrane due to a transmembrane region in the N-terminus of the protein. At the subcellular level, SPATA46-deficient condensed spermatids displayed structural defects consisting of a discontinuous nuclear envelope and a cavity in the nucleus associated with an abnormal nuclear shape. Additionally, in vitro, we determined that the absence of SPATA46 led to accumulation of sperm around the perivitelline space of eggs, and the same phenomenon was also observed for natural sperm incubated with an anti-SPATA46 antibody, suggesting functional relevance of SPATA46 for sperm-egg fusion. Taken together, these results indicated that SPATA46 is a novel protein involved in reshaping of the sperm head and sperm-egg fusion.

Identification of NR0B1 as a novel androgen receptor co-repressor in mouse Sertoli cells.

Nuclear receptor subfamily 0 group B member 1 (Nr0b1) is an atypical member of the nuclear receptor family that is predominantly expressed in mouse Sertoli cells (SCs). Mutations of NR0B1 in humans cause adrenal failure and hypogonadotropic hypogonadism. The targeted mutagenesis of Nr0b1 in mice has revealed a primary gonadal defect characterized by the overexpression of aromatase and cellular obstruction of the seminiferous tubules and efferent ductules, leading to germ cell death and infertility. The transgenic expression of Nr0b1 under the control of the Müllerian-inhibiting substance promoter (MIS-Nr0b1), which is selectively expressed in SCs, improves fertility. Testicular androgen receptor (AR) was also expressed in SCs. Many genes are directly regulated by androgen and its AR, which are involved in spermatogenesis and male infertility. As the association between NR0B1 and AR remains unclear in mouse SCs, we decided to further explore the relationship between them. In the present study, we have identified NR0B1 as a novel AR co-repressor in mouse SCs. Using RT­qPCR and immunofluorescence, we determined that NR0B1 was mainly expressed in mouse SCs in an age-dependent manner from 2-8 weeks of age postnatally. The inhibition of the effects of AR on AR target genes by NR0B1, in an androgen­dependent manner, was further demonstrated by western blot analysis and RT-qPCR in TM4 cells, a mouse Sertoli cell line. Finally, in vitro luciferase and co-immunoprecipitation assays validated that NR0B1, as an AR co-repressor, significantly inhibited the transcriptional activation of its target genes. These results suggest that novel inhibitory mechanisms underlie the effects of NR0B1 in modulating androgen-dependent gene transcription in mouse SCs.

Identification and characteristics of the testes-specific gene, Ccdc38, in mice.

Distinguishing the testes-specific genes in different species may disclose key genes associated with testes-specific functions and provide sufficient information for the study and treatment of male infertility. A testes­specific gene, coiled-coil domain containing 38 (Ccdc38), was identified by screening UniGene libraries. Systematic bioinformatics analysis demonstrated that the CCDC38 protein was conserved in various mammalian species. It was determined that CCDC38 was exclusively expressed in testes and its expression increased from 2­8 weeks of age. Additional immunohistochemical analysis indicated that CCDC38 was mainly expressed in spermatogonia and spermatocytes. It is of note that, immunofluorescence and co-immunoprecipitation assays demonstrated that CCDC38 interacted with ubiquitinated histone H2A in mouse testes. Therefore, these results suggest that Ccdc38 is a testes-specific gene, which may be important for mouse spermatogenesis.

[Expression characteristics of the Ccdc70 gene in the mouse testis during spermatogenesis].

OBJECTIVE: To investigate the expression characteristics of the gene of coiled-coil domain-containing protein 70 (Ccdc70) in the mouse testis and its potential role in spermatogenesis. METHODS: Using expression profile microarray, we screened the mouse testis-specific gene Ccdc70, studied its expression characteristics in the mouse testis by RT-PCR, real-time PCR, Western blot and immunohistochemistry, followed by bioinformatic analysis of the Ccdc70 protein. RESULTS: The Ccdc70 gene was expressed highly in the testis but lowly in the epididymis of the mice. The Ccdc70 protein was expressed mainly in the spermatocytes and round spermatids of the testis and in the epithelial cells of the epididymis. Bioinformatic analysis showed a structural domain in the Ccdc70 protein, which was highly conserved in mammalian evolution. CONCLUSION: The Ccdc70 gene is highly expressed in the mouse testis and mainly in the spermatocytes, round spermatids, and epididymal epithelial cells, which indicates that it is involved in the regulation of spermatogenesis and epididymal sperm maturation.

Protein Arginine Methyltransferase 6 Involved in Germ Cell Viability during Spermatogenesis and Down-Regulated by the Androgen Receptor.

Androgens and the androgen receptor (AR) are of great importance to spermatogenesis and male fertility. AR knockout (ARKO) mice display a complete insensitivity to androgens and male infertility; however, the exact molecular mechanism for this effect remains unclear. In this study, we found that the expression levels of Prmt6 mRNA and protein were significantly up-regulated in the testes of ARKO mice compared to wild type (WT) mice. PRMT6 was principally localized to the nucleus of spermatogonia and spermatocytes by immunofluorescence staining. Furthermore, luciferase assay data showed that AR together with testosterone treatment suppressed Prmt6 transcription via binding to the androgen-responsive element (ARE) of the Prmt6 promoter. Moreover, knockdown of Prmt6 suppressed germ cells migration and promoted apoptosis. In addition, both of these cellular activities could not be enhanced by testosterone treatment. Taken together, these data indicate that PRMT6, which was down-regulated by AR and influenced cell migration and apoptosis of germ cells, could play a potentially important role in spermatogenesis.

Androgen receptor binding to an androgen-responsive element in the promoter of the Srsf4 gene inhibits its expression in mouse Sertoli cells.

The serine/arginine-rich splicing actor 4 (SRSF4) is essential for pre-mRNA splicing and can influence alternative-splice-site choice. Little is known about the specific function of this gene in the reproductive system, although a recent study identified a SRSF4 polymorphism significantly associated with a decreased risk of non-obstructive azoospermia in Chinese men. We previously found that the expression of Srsf4 was up-regulated in the testes of Sertoli-cell-selective androgen receptor knockout (S-Ar(-/y)) mice compared to wild-type mice using digital gene expression analysis. In this study, we confirmed and extended the selective gene expression data: SRSF4 was mainly located in the nucleus of Sertoli cells, and Srsf4 expression in the Sertoli-cell-derived cell line TM4 is down-regulation by testosterone. Moreover, androgen receptor directly binds the androgen-responsive element of the Srsf4 promoter. Taken together, these results demonstrate that Srsf4 is a direct downstream target of the androgen receptor in mouse Sertoli cells.

FAM170B, a novel acrosomal protein involved in fertilization in mice.

The acrosome is a specialized organelle that covers the anterior region of the sperm nucleus, and plays an essential role in mammalian fertilization. Although acrosome biogenesis is an important aspect of spermiogenesis, the molecular mechanism that regulates this event remains unknown. In the present study, we identified a novel gene, Fam170b (family with sequence similarity 170, member B), exclusively expressed in mouse testes. Fam170b expression first started at postnatal week 3, and increased in an age-dependent manner until plateauing in adulthood. Immunofluorescence staining revealed its enrichment in round spermatids, and redistribution to a perinuclear spot adjacent to the Golgi and the acrosome of elongating spermatids and spermatozoa; this localization was shared between mouse and human spermatozoa. Anti-FAM170B antibody was remarkably found to inhibit murine in vitro fertilization, specifically blocking the acrosome reaction. We further determined that FAM170B interacts with GOPC (Golgi-associated PDZ and coiled-coil motif containing protein) during acrosome formation, as verified by immunofluorescence and co-immunoprecipitation assays. Thus, we document the expression and function for the endogenous acrosomal protein FAM170B during spermiogenesis and fertilization.

[Expression of a testis-specific gene 1700001022RIK in mice and its bioinformatic analysis].

OBJECTIVE: To identify the expression characteristics of the 1700001022RIK (RIKEN cDNA 1700001022) gene in mice and explore its function by bioinformatic analysis. METHODS: Using the expression profile of gene microarray, we detected the expression of a new testis-specific gene, 1700001022RIK, in mice. We analyzed its expression characteristics in the testis tissue and their changes in different developmental stages of the testis by RT-PCR, real-time RT-PCR, Western blot, and immunohistochemistry. We performed bioinformatic analysis using a bioinformatic software. RESULTS: The 1700001022RIK gene was specifically expressed in the mouse testis in an age-dependent manner, most highly in the adult mice. The 1700001022RIK protein was mainly expressed in the spermatogonia, spermatocytes, and round spermatids of the adult mice. Bioinformatic analysis showed that the 1700001022RIK protein amino acid sequence had a high similarity in human and mice, which indicated that this gene was highly conserved in mammals. CONCLUSION: 1700001022RIK is a testis-specific gene mainly expressed in the spermatogonia, spermatocytes, and round spermatids of seminiferous tubules, which might be involved in the regulation of spermatogenesis.