E3 ubiquitin ligase ASB17 is required for spermiation in mice

Testis-enriched Socs7 is not essential for spermatogenesis and male fertility in mice

OBJECTIVES

As a crucial member of the Suppressor of Cytokine Signaling (SOCS) family, SOCS7 regulates various physiological processes, including insulin resistance, inflammation, and tumor suppression. However, its role in male germ cells remains poorly understood. This study aims to investigate the function of SOCS7 in spermatogenesis and uncover its potential regulatory mechanisms.

METHODS

We conducted bioinformatics analyses to examine the expression profile of Socs7 in the testes, generated Socs7-knockout (KO) mice using CRISPR/Cas9 genome editing, and assessed testicular morphology through histological and immunohistochemical staining. Semen quality was evaluated using computer-assisted sperm analysis (CASA), and testicular apoptosis was examined using the terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay.

RESULTS

Bioinformatics analysis revealed high expression of Socs7 in both human and mouse testes. However, Socs7-KO mice exhibited normal fertility, with no significant differences in testicular morphology, sperm quality, or spermatogenesis compared to wild-type (WT) mice. Additionally, testicular apoptosis in Socs7-KO mice was not significantly altered.

CONCLUSIONS

Our study demonstrates that although Socs7 is highly expressed in the testes, its deletion does not impair male fertility or spermatogenesis in mice. These findings provide valuable insights into the role of SOCS7 in male reproduction and help prevent unnecessary duplication of research efforts.

Testis-enriched Spsb1 is not required for spermatogenesis and fertility in mice

OBJECTIVES

SPRY (repeats in splA and RyR) domain-containing SOCS (suppressor of cytokine signaling) box protein 1 (SPSB1) is an E3 ligase adaptor protein that has been implicated in various cellular processes and physiological pathways. However, its role in spermatogenesis remains poorly understood. The objective of this study was to investigate the impact of SPSB1 deficiency on spermatogenesis and male fertility in mice.

METHODS

We generated Spsb1 knockout (Spsb1-KO) mice to explore the effects of SPSB1 deficiency on sperm quality. To assess sperm parameters, we utilized computer-assisted sperm analysis (CASA), which provides precise measurements of sperm motility, concentration, and morphology. Additionally, histological and immunohistochemical analyses were performed to evaluate the influence of SPSB1 deficiency on spermatogenesis.

RESULTS

Our results showed no significant differences in semen quality, fertility, or histological findings between Spsb1-KO and wild-type (WT) mice.

CONCLUSIONS

This study demonstrates that SPSB1 is not essential for spermatogenesis or male fertility in mice. These findings provide a valuable resource for future genetic investigations into human fertility and help prevent unnecessary duplication of research efforts in this area.

Spsb3 is not essential for spermatogenesis and male fertility in mice

BACKGROUND

Spermatogenesis, the process by which male germ cells develop into mature spermatozoa, is a complex and highly regulated phenomenon crucial for male fertility. Various molecular pathways, including ubiquitination, play critical roles in this process. Ubiquitination regulates multiple stages of spermatogenesis by controlling cell remodeling and protein metabolism. SplA/ryanodine receptor domain and SOCS box containing 3 (SPSB3), a SOCS box protein, interacts with ElonginC/B and recruits Cullin5 to form the ECS E3 ligase complex, which is involved in cell development, proliferation, stress response, and apoptosis. However, the specific role of SPSB3 in spermatogenesis and male reproduction remains poorly understood.

METHODS

The distribution and expression of Spsb3 were analyzed using bioinformatics approaches. Spsb3-knockout (KO, Spsb3-/- ) mice were generated using CRISPR/Cas9 gene editing. Sperm quality was assessed using a computer assisted sperm analysis (CASA) system. Histological and immunostaining analyses were performed to evaluate the effects of Spsb3 deletion on mouse testicular structure. Apoptotic cells were detected using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL).

RESULTS

Our findings indicate that Spsb3 is a testis-enriched gene in mice. However, no significant differences were observed in sperm quality, fertility, or testis histology between Spsb3 -/- and wild-type (WT) adult mice.

CONCLUSION

This is the first functional study of Spsb3 in mammalian reproduction. Despite its evolutionary conservation and high testicular expression, Spsb3 is not essential for mouse spermatogenesis under physiological conditions.

ASB1 engages with ELOB to facilitate SQOR ubiquitination and H2S homeostasis during spermiogenesis

Male infertility, frequently driven by oxidative stress, impacts half of infertile couples globally. Despite its significance, the precise mechanisms governing this process remain elusive. In this study, we demonstrate that ASB1, the substrate recognition subunit of a ubiquitin ligase, is highly expressed in the mouse testis. Mice lacking the Asb1 gene exhibit severe fertility impairment, characterized by oligoasthenoteratozoospermia. Subsequent investigations unveiled that Asb1 knockout (Asb1-KO) mice encountered excessive oxidative stress and decreased hydrogen sulfide (H2S) levels in their testes, and severe sperm DNA damage. Notably, the compromised fertility and sperm quality in Asb1-KO mice was significantly ameliorated by administering NaHS, a H2S donor. Mechanistically, ASB1 interacts with ELOB to induce the instability of sulfide-quinone oxidoreductase (SQOR) by enhancing its K48-linked ubiquitination on residues K207 and K344, consequently triggering proteasomal degradation. This process is crucial for preserving H2S homeostasis and redox balance. Overall, our findings offer valuable insights into the role of ASB1 during spermiogenesis and propose H2S supplementation as a promising therapeutic approach for oxidative stress-related male infertility.

Cross-ancestry meta-genome-wide association studies provide insights to the understanding of semen traits in pigs

Semen traits play a crucial role in pig reproduction and fertility. However, limited data availability hinder a comprehensive understanding of the genetic mechanisms underlying these traits. In this study, we integrated 597 299 ejaculates and 3 596 sequence data to identify genetic variants and candidate genes related to four semen traits, including sperm progressive motility (MOT), semen volume, sperm concentration (CON), and effective sperm count (SUM). A cross-ancestry meta-genome-wide association study was conducted to detect 163 lead single nucleotide polymorphisms (SNPs) associated with MOT, CON, and SUM. Subsequently, transcriptome-wide association studies and colocalisation analyses were integrated to identify 176 candidate genes, many of which have documented roles in spermatogenesis or male mammal semen traits. Our analysis highlighted the potential involvement of CSM5, PDZD9, and LDAF1 in regulating semen traits through multiple methods. Finally, to validate the function of significant SNPs, we performed genomic feature best linear unbiased prediction in 348 independent pigs using identified trait-related SNP subsets as genomic features. We found that integrating the top 0.1, 1, and 5% significant SNPs as genomic features could enhance genomic prediction accuracy for CON and MOT compared to traditional genomic best linear unbiased prediction. This study contributes to a comprehensive understanding of the genetic mechanisms of boar semen traits and provides insight for developing genomic selection models.

Transcriptomic Characterization of Male Formosan Pangolin (Manis pentadactyla pentadactyla) Reproductive Tract and Evaluation of Domestic Cat (Felis catus) as a Potential Model Species

The Formosan pangolin (Manis pentadactyla pentadactyla) is an endemic animal of Taiwan. Due to their reduced population and behavior, very little is known about this enigmatic species. To unravel male pangolin reproduction, in the present study, we built a complete genomic database of the male Formosan pangolin reproductive tract and revealed highly expressing genes as well as critical signaling pathways and their associated biological processes in both the testis and the epididymis. Moreover, we evaluated the domestic cat (Felis catus) as a potential model species for male pangolin reproduction by comparing their testicular transcriptomes. We demonstrated a clear tissue-specific gene expression supporting the unique biological signature of each reproductive tissue and identified critical genes of the different reproductive organs. Pathway enrichment analysis revealed unique pathways in the testis as well as a clear epididymal transition. Furthermore, domestic cats, despite being the closest domestic species to pangolin, demonstrated their unfitness as a male reproduction model species as clear differences in spermatid differentiation and metabolism were observed. These results enable a better understanding of male pangolin reproduction characteristics and may inspire improvements in in Formosan pangolin conservation strategies.

E3 ligase FBXO22 is not significant for spermatogenesis and male fertility in mice

BACKGROUND

F-box-only protein 22 (FBXO22), an important substrate receptor of the SKP1-Cullin-F-box (SCF) ubiquitin ligases, has been reported to be involved in many biological processes, including tumorigenesis, neurological disorders, cellular senescence, and DNA damage. However, the specific role of FBXO22 during spermatogenesis is poorly understood.

METHODS

We produced Fbxo22 conditional knockout (cKO) and global knockout (KO) mice and assessed their sperm masurements using a computer-assisted sperm analysis (CASA) system. Additionally, we conducted histologic staining and immunostaining to examine the impact of Fbxo22 loss on spermatogenesis.

RESULTS

Our results revealed that there were no notable differences in semen quality, fertility test results, or histologic findings in Fbxo22-KO and Fbxo22-cKO mice compared to the control group.

CONCLUSIONS

Our study demonstrated that Fbxo22 is not significant for spermatogenesis or male fertility in mice. These findings will help researchers avoid redundant efforts and serve as a foundational resource for genetic studies on human fertility.

Slc26a1 is not essential for spermatogenesis and male fertility in mice

Thousands of genes are expressed in the testis of mice. However, the details about their roles during spermatogenesis have not been well-clarified for most genes. The purpose of this study was to examine the effect of Slc26a1 deficiency on mouse spermatogenesis and male fertility. Slc26a1-knockout (KO) mice were generated using CRISPR/Cas9 technology on C57BL/6J background. We found no obvious differences between Slc26a1-KO and Slc26a1-WT mice in fertility tests, testicular weight, sperm concentrations, or morphology. Histological analysis found that Slc26a1-KO mouse testes had normal germ cell types and mature sperm. These findings indicated that Slc26a1 was dispensable for male fertility in mice. Our results may save time and resources by allowing other researchers to focus on genes that are more meaningful for fertility studies. We also found that mRNAs of two Slc26a family members (Slc26a5 and Slc26a11) were expressed on higher mean levels in Slc26a1-KO total mouse testes, compared to Slc26a1-WT mice. This effect was not found in mouse GC-1 and GC-2 germ cell lines with the Slc26a1 gene transiently knocked down. This result may indicate that a gene compensation phenomenon was present in the testes of Slc26a1-KO mice.

Long non-coding RNA NRSN2-AS1 promotes ovarian cancer progression through targeting PTK2/β-catenin pathway

As a common malignant tumor among women, ovarian cancer poses a serious threat to their health. This study demonstrates that long non-coding RNA NRSN2-AS1 is over-expressed in ovarian cancer tissues using patient sample and tissue microarrays. In addition, NRSN2-AS1 is shown to promote ovarian cancer cell proliferation and metastasis both in vitro and in vivo. Mechanistically, NRSN2-AS1 stabilizes protein tyrosine kinase 2 (PTK2) to activate the β-catenin pathway via repressing MG-53-mediated ubiquitinated degradation of PTK2, thereby facilitating ovarian cancer progression. Rescue experiments verify the function of the NRSN2-AS1/PTK2/β-catenin axis and the effects of MG53 on this axis in ovarian cancer cells. In conclusion, this study demonstrates the key role of the NRSN2-AS1/PTK2/β-catenin axis for the first time and explores its potential clinical applications in ovarian cancer.

Testis-enriched Asb15 is not required for spermatogenesis and male fertility in mice

BACKGROUND

The function of Asb15, which encodes an ASB protein with ankyrin (ANK) repeats and a C-terminal suppressor of cytokine signaling (SOCS) box motif, in male germ cells is poorly understood. Because expression of Asb15 is enriched in mouse testis, it may have a role in spermatogenesis.

METHODS AND RESULTS

We used a computer-assisted sperm analysis (CASA) system to analyze sperm from Asb15 gene knockout (KO) mice that we generated using the clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (Cas9) technique. Histological staining and immunostaining were used to evaluate spermatogenesis in Asb15-KO mice. Asb15-KO and wild-type mice showed no differences in histology or in semen quality, fertility, or sperm apoptosis. Asb15- and Asb17-double KO (dKO) mice were generated to determine whether Asb17 compensated for the loss of Asb15. However, Asb15/17-dKO mice also showed normal fertility, except for an increase in giant cells in testicular tubules, suggesting a minor functional compensation between the two genes during spermatogenesis.

CONCLUSIONS

Our study suggests that Asb15 was individually not required for spermatogenesis or for fertility in mice. However, further investigation might be needed to reach a firm conclusion. These findings can prevent redundant research by other scientists and provides new information for further studies on the genetics of fertility in humans.

Identification of proline-rich protein 11 as a major regulator in mouse spermatogonia maintenance via an increase in BMI1 protein stability

BACKGROUND

Spermatogenesis accompanied by self-renewal and differentiation of spermatogonia under complicated regulation is crucial for male fertility. Our previous study demonstrated that the loss of the B-lymphoma Mo-MLV insertion region 1 (BMI1) could cause male infertility and found a potential interaction between BMI1 and proline-rich protein 11 (PRR11); however, the specific co-regulatory effects of BMI1/PRR11 on spermatogonia maintenance remain unclear.

METHODS AND RESULTS

The expression of PRR11 was downregulated in a mouse spermatogonia cell line (GC-1) via transfection with PRR11-siRNAs, and PRR11 knockdown was verified by real-time reverse transcriptase polymerase chain reaction (RT-qPCR). The proliferative activity of GC-1 cells was determined using the cell counting kit (CCK-8), colony formation, and 5-ethynyl-2-deoxyuridine (EdU) incorporation assay. A Transwell assay was performed to evaluate the effects of PRR11 on GC-1 cell migration. A terminal deoxynucleotidyl transferase dUTP nick end labeling assay was used to measure GC-1 cell apoptosis. Furthermore, co-immunoprecipitation, RT-qPCR, and western blot analyses were used for investigating the regulatory mechanisms involved in this regulation. It was found that downregulation of PRR11 could cause a marked inhibition of proliferation and migration and induced apoptosis in GC-1 cells. Moreover, silencing of PRR11 obviously led to a reduction in the BMI1 protein level. PRR11 was found to interact with BMII at the endogenous protein level. PRR11 knockdown produced a decrease in BMI1 protein stability via an increase in BMI1 ubiquitination after which derepression in the transcription of protein tyrosine phosphatase receptor type M (Ptprm) occurred. Importantly, knockdown of Ptprm in PRR11-deficient GC-1 cells led to a reversal of proliferation and migration of GC-1 cells.

CONCLUSIONS

This study uncovered a novel mechanism by which PRR11 cooperated with BMI1 to facilitate GC-1 maintenance through targeting Ptprm. Our findings may provide a better understanding of the regulatory network in spermatogonia maintenance.

Application of CRISPR/Cas Technology in Spermatogenesis Research and Male Infertility Treatment

As the basis of animal reproductive activity, normal spermatogenesis directly determines the efficiency of livestock production. An in-depth understanding of spermatogenesis will greatly facilitate animal breeding efforts and male infertility treatment. With the continuous development and application of gene editing technologies, they have become valuable tools to study the mechanism of spermatogenesis. Gene editing technologies have provided us with a better understanding of the functions and potential mechanisms of action of factors that regulate spermatogenesis. This review summarizes the applications of gene editing technologies, especially CRISPR/Cas9, in deepening our understanding of the function of spermatogenesis-related genes and disease treatment. The problems of gene editing technologies in the field of spermatogenesis research are also discussed.