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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. [ABSTRACT FROM AUTHOR]

Study Question: Is there an association between sperm DNA methylation profiles and asthenozoospermia?Summary Answer: DNA methylation, at specific CpGs but not at the global level, was significantly different between low motile sperm cells of asthenozoospermic individuals and high motile sperm cells of normozoospermic controls.What Is Known Already: Aberrant DNA methylation, both globally and restricted to a specific gene locus, has been associated with male infertility and abnormal semen parameters.Study Design, Size, Duration: This was a case-control study investigating the differences in DNA methylation at CpGs in promoter regions between high and low motile sperm cells from eight normozoospermic controls and seven asthenozoospermic patients.Participants/materials, Setting, Methods: The liquid hybridization capture-based bisulfite sequencing method was used to determine DNA methylation at CpGs in promoter regions. The global inter-individual and intra-individual methylation variability were estimated by evaluating the methylation variance between and within different motile sperm fractions from the same or different individuals. Asthenozoospermia-associated differentially methylated or variable CpGs and differentially methylated regions were identified by comparing the DNA methylation of high motile sperm cells from normozoospermic controls with that of low motile sperm cells from asthenozoospermic patients.Main Results and the Role Of Chance: In this study, we determined the global DNA methylation level (24.7%), inter-individual variance (14.4%) and intra-individual differences between high and low motile sperm fractions (3.9%). We demonstrated that there were no statistically significant differences in either the global DNA methylation level or global methylation variability between sperm from men with normozoospermia or asthenozoospermia. Between high motile sperm from men with normozoospermia and low motile sperm from men with asthenozoospermia, we identified 134 differentially methylated CpGs, 41 differentially methylated regions and 134 differentially variable CpGs. The genomic distribution patterns of the differential methylation spectrum suggested that gene expression may be affected in low motile sperm cells of asthenozoospermic patients. Finally, through a functional analysis, we detected 16 differentially methylated or variable genes that are required for spermatogenesis and sperm motility or dominantly expressed in testis.Limitations, Reasons For Caution: The sample size in this study was limited, although the participants in the two groups were carefully selected and well matched. Our results must be verified in larger cohorts with the use of different techniques. Furthermore, our results were descriptive, and follow-up studies will be needed to elucidate the effect of differential methylation profiles on asthenozoospermia.Wider Implications Of the Findings: Our study identified asthenozoospermia-associated DNA methylation profiles and proposed a list of genes, which were suggested to be involved in the regulation of sperm motility through an alteration of DNA methylation. These results will provide promising clues for understanding the effect of DNA methylation on sperm motility and asthenozoospermia.Study Funding/competing Interests: This study was funded primarily by the National Natural Science Foundation of China, Shenzhen Project of Science and Technology and the National Basic Research Program of China. The authors have no competing interests. [ABSTRACT FROM AUTHOR]

BACKGROUND Spermatogenesis is maintained by a dynamic balance between germ cell proliferation and apoptosis. Previous study has demonstrated that CD147 knockout mice are infertile with arrested germ cells. However, the question of whether and how CD147 may be involved in the apoptotic process during spermatogenesis remains elusive. The aim of this study was to evaluate the role of CD147 in the regulation of germ cell apoptosis in mice. METHODS CD147 function was blocked by anti-CD147 antibody in GC-1 (immortalized spermatogonia) and GC-2 (immortalized spermatocytes) cell lines and in testicular germ cells in vivo. Testes size and weight were examined after injection of anti-CD147 antibody into the seminiferous tubules of severe combined immunodeficiency mice. Germ cell apoptosis was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay and levels of p53 and two effectors, caspase 3 and poly ADP-ribose polymerase (PARP), using western blots. RESULTS The size and weight of the CD147-immunodepleted testes were decreased compared with that in control testes (P < 0.001). The TUNEL assay showed an increase in the number of apoptotic spermatocytes (P < 0.001 versus control) but not spermatogonia in Stages XI–XII of CD147-immunodepleted testes. In addition, in vitro experiments demonstrated that CD147 immunodepletion induced an increase in apoptosis in GC-2 cells (P < 0.001 versus control) but had no effect on GC-1 cells. Moreover, deprivation of CD147 induced apoptosis in spermatocytes through a p53-independent mechanism, which led to caspase 3 and PARP activation. CONCLUSIONS We have demonstrated that immunodepletion of CD147 induces p53-independent apoptosis in mouse spermatocytes but not spermatogonia. [ABSTRACT FROM AUTHOR]