scholarly journals Cytosine methylation dynamics during post-testicular sperm maturation in mammals

2020 ◽  
Author(s):  
Carolina Galan ◽  
Ryan W. Serra ◽  
Fengyun Sun ◽  
Vera D. Rinaldi ◽  
Colin C. Conine ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cytosine Methylation ◽  
Reproductive Tract ◽  
Extracellular Dna ◽  
Cell Populations ◽  
Epididymal Sperm ◽  
Sequencing Data ◽  
Testicular Germ Cell ◽  
Mammalian Sperm ◽  
The Stability

ABSTRACTBeyond the haploid genome, mammalian sperm contribute a payload of epigenetic information which can modulate offspring phenotypes. Recent studies have shown that the small RNA payload of sperm undergoes extensive remodeling during post-testicular maturation in the epididymis. Intriguingly, epididymal maturation has also been linked to changes in the sperm methylome, suggesting that the epididymis might play a broader role in remodeling the sperm epigenome. Here, we build on prior studies of the maturing sperm methylation landscape, further characterizing the genome-wide methylation landscape in seven germ cell populations collected from throughout the male reproductive tract. Overall, we find very few changes in the cytosine methylation landscape between testicular germ cell populations and cauda epididymal sperm, demonstrating that the sperm methylome is largely stable throughout post-testicular maturation. Intriguingly, although our sequencing data suggested that caput epididymal sperm exhibit a highly unusual methylome, follow-up studies revealed that this resulted from contamination of caput sperm by extracellular DNA. Extracellular DNA formed web-like structures that ensnared sperm, was present only in the caput epididymis of virgin males, where it was associated with citrullinated histone H3 and presumably resulted from a PAD-driven genome decondensation process. Taken together, our data emphasize the stability of the cytosine methylation landscape in mammalian sperm, and identify a surprising but transient period during which immature sperm are associated with extracellular DNA.

scholarly journals Stability of the cytosine methylome during post-testicular sperm maturation in mouse

PLoS Genetics ◽  
2021 ◽  
Vol 17 (3) ◽  
pp. e1009416
Author(s):  
Carolina Galan ◽  
Ryan W. Serra ◽  
Fengyun Sun ◽  
Vera D. Rinaldi ◽  
Colin C. Conine ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cytosine Methylation ◽  
Reproductive Tract ◽  
Extracellular Dna ◽  
Cell Populations ◽  
Epididymal Sperm ◽  
Sequencing Data ◽  
Testicular Germ Cell ◽  
Mammalian Sperm ◽  
The Stability

Beyond the haploid genome, mammalian sperm carry a payload of epigenetic information with the potential to modulate offspring phenotypes. Recent studies show that the small RNA repertoire of sperm is remodeled during post-testicular maturation in the epididymis. Epididymal maturation has also been linked to changes in the sperm methylome, suggesting that the epididymis might play a broader role in shaping the sperm epigenome. Here, we characterize the genome-wide methylation landscape in seven germ cell populations from throughout the male reproductive tract. We find very few changes in the cytosine methylation landscape between testicular germ cell populations and cauda epididymal sperm, demonstrating that the sperm methylome is stable throughout post-testicular maturation. Although our sequencing data suggested that caput epididymal sperm exhibit a highly unusual methylome, follow-up studies revealed that this resulted from contamination of caput sperm by extracellular DNA. Extracellular DNA formed web-like structures that ensnared sperm, and was present only in sperm samples obtained from the caput epididymis and vas deferens of virgin males. Curiously, contaminating extracellular DNA was associated with citrullinated histone H3, potentially resulting from a PAD-driven genome decondensation process. Taken together, our data emphasize the stability of cytosine methylation in mammalian sperm, and identify a surprising, albeit transient, period during which sperm are associated with extracellular DNA.

scholarly journals Vinclozolin Exposure in Utero Induces Postpubertal Prostatitis and Reduces Sperm Production via a Reversible Hormone-Regulated Mechanism

Endocrinology ◽  
2010 ◽  
Vol 151 (2) ◽  
pp. 783-792 ◽  
Author(s):  
Prue A. Cowin ◽  
Elspeth Gold ◽  
Jasna Aleksova ◽  
Moira K. O'Bryan ◽  
Paul M. D. Foster ◽  
...  
Keyword(s):  
Germ Cell ◽  
Cell Apoptosis ◽  
Reproductive Tract ◽  
Nuclear Factor Κb ◽  
In Utero ◽  
High Dose ◽  
Nuclear Factor ◽  
Testicular Germ Cell ◽  
Male Reproductive Tract ◽  
Germ Cell Apoptosis

Vinclozolin is an endocrine-disrupting chemical (EDC) that binds with high affinity to the androgen receptor (AR) and blocks the action of gonadal hormones on male reproductive organs. An alternative mechanism of action of Vinclozolin involves transgenerational effects on the male reproductive tract. We previously reported in utero Vinclozolin exposure-induced prostatitis (prostate inflammation) in postpubertal rats concurrent with down-regulation of AR and increased nuclear factor-κB activation. We postulated the male reproductive abnormalities induced by in utero Vinclozolin exposure could be reversed by testosterone supplementation, in contrast to the permanent modifications involving DNA methyltransferases (Dnmts) described by others. To test this hypothesis, we administered high-dose testosterone at puberty to Vinclozolin-treated rats and determined the effect on anogenital distance (AGD); testicular germ cell apoptosis, concentration of elongated spermatids, and the onset of prostatitis. Concurrently we examined Dnmt1, −3A, −3B, and −3L mRNA expression. Consistent with previous reports, in utero exposure to Vinclozolin significantly reduced AGD, increased testicular germ cell apoptosis 3-fold, reduced elongated spermatid number by 40%, and induced postpubertal prostatitis in 100% of exposed males. Administration of high-dose testosterone (25 mg/kg) at puberty normalized AGD, reduced germ cell apoptosis, and restored elongated spermatid number. Testosterone restored AR and nuclear factor-κB expression in the prostate and abolished Vinclozolin-induced prostatitis. Altered Dnmt expression was evident with in utero Vinclozolin exposure and was not normalized after testosterone treatment. These data demonstrate in utero Vinclozolin-induced male reproductive tract abnormalities are AR mediated and reversible and involve a mechanism independent of Dnmt expression.

scholarly journals Integrated analysis of high-throughput sequencing data reveals the key role of LINC00467 in the invasion and metastasis of testicular germ cell tumors

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hao Bo ◽  
Fang Zhu ◽  
Zhizhong Liu ◽  
Qi Deng ◽  
Guangmin Liu ◽  
...  
Keyword(s):  
Germ Cell ◽  
High Throughput Sequencing ◽  
Expression Profiles ◽  
Germ Cell Tumors ◽  
Differentially Expressed ◽  
Migration And Invasion ◽  
Integrated Analysis ◽  
Sequencing Data ◽  
Testicular Germ Cell

AbstractLong noncoding RNAs (lncRNAs) are involved in various physiological and pathological processes. However, the role of lncRNAs in testicular germ cell tumor (TGCT) has been rarely reported. Our purpose is to comprehensively survey the expression and function of lncRNAs in TGCT. In this study, we used RNA sequencing to construct the lncRNA expression profiles of 13 TGCT tissues and 4 paraneoplastic tissues to explore the function of lncRNAs in TGCT. The bioinformatics analysis showed that many lncRNAs are differentially expressed in TGCT. GO and KEGG enrichment analyses revealed that the differentially expressed lncRNAs participated in various biological processes associated with tumorigenesis in cis and trans manners. Further, we found that the expression of LINC00467 was positively correlated with the poor prognosis and pathological grade of TGCT using WGCNA analysis and GEPIA database data mining. In vitro experiments revealed that LNC00467 could promote the migration and invasion of TGCT cells by regulating the expression of AKT3 and influencing total AKT phosphorylation. Further analysis of TCGA data revealed that the expression was negatively correlated with the infiltration of immune cells and the response to PD1 immunotherapy. In summary, this study is the first to construct the expression profile of lncRNAs in TGCT. It is also the first study to identify the metastasis-promoting role of LNC00467, which can be used as a potential predictor of TGCT prognosis and immunotherapeutic response to provide a clinical reference for the treatment and diagnosis of TGCT metastasis.

scholarly journals ScaR—a tool for sensitive detection of known fusion transcripts: establishing prevalence of fusions in testicular germ cell tumors

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Sen Zhao ◽  
Andreas M Hoff ◽  
Rolf I Skotheim
Keyword(s):  
Germ Cell ◽  
Germ Cell Tumors ◽  
Simulated Data ◽  
High Sensitivity ◽  
Fusion Transcript ◽  
Data Sets ◽  
Testicular Germ Cell Tumors ◽  
Sequencing Data ◽  
Testicular Germ Cell ◽  
Fusion Transcripts

Abstract Bioinformatics tools for fusion transcript detection from RNA-sequencing data are in general developed for identification of novel fusions, which demands a high number of supporting reads and strict filters to avoid false discoveries. As our knowledge of bona fide fusion genes becomes more saturated, there is a need to establish their prevalence with high sensitivity. We present ScaR, a tool that uses a supervised scaffold realignment approach for sensitive fusion detection in RNA-seq data. ScaR detects a set of 130 synthetic fusion transcripts from simulated data at a higher sensitivity compared to established fusion finders. Applied to fusion transcripts potentially involved in testicular germ cell tumors (TGCTs), ScaR detects the fusions RCC1-ABHD12B and CLEC6A-CLEC4D in 9% and 28% of 150 TGCTs, respectively. The fusions were not detected in any of 198 normal testis tissues. Thus, we demonstrate high prevalence of RCC1-ABHD12B and CLEC6A-CLEC4D in TGCTs, and their cancer specific features. Further, we find that RCC1-ABHD12B and CLEC6A-CLEC4D are predominantly expressed in the seminoma and embryonal carcinoma histological subtypes of TGCTs, respectively. In conclusion, ScaR is useful for establishing the frequency of known and validated fusion transcripts in larger data sets and detecting clinically relevant fusion transcripts with high sensitivity.

scholarly journals Small RNAs are trafficked from the epididymis to developing mammalian sperm

2017 ◽  
Author(s):  
Upasna Sharma ◽  
Fengyun Sun ◽  
Brian Reichholf ◽  
Veronika A. Herzog ◽  
Stefan L. Ameres ◽  
...  
Keyword(s):  
Germ Cell ◽  
Small Rna ◽  
Small Rnas ◽  
Mature Sperm ◽  
Metabolic Labeling ◽  
Testicular Germ Cell ◽  
Testicular Spermatozoa ◽  
Mammalian Sperm ◽  
Low Levels

SummaryRNAs present in mature mammalian sperm are delivered to the zygote at fertilization, where they have the potential to affect early development. The biogenesis of the small RNA payload of mature sperm is therefore of great interest, as it may be a target of signaling pathways linking paternal conditions to offspring phenotype. Recent studies have suggested the surprising hypothesis that the small RNA payload carried by mature sperm may include RNAs that were not synthesized during testicular spermatogenesis, but that are instead delivered to sperm during the process of post-testicular maturation in the epididymis. To further test this hypothesis, we characterized small RNA dynamics during testicular and post-testicular germ cell maturation in mice. We show that purified testicular germ cell populations, including mature testicular spermatozoa, carry extremely low levels of tRNA fragments (tRFs), and that tRFs become highly abundant only after sperm have entered the epididiymis. The process of small RNA delivery to sperm can be recapitulated in vitro, as caput epididymosomes deliver small RNAs including tRFs and microRNAs to mature testicular spermatozoa. Finally, to definitively identify the tissue of origin for small RNAs in sperm, we carried out tissue-specific metabolic labeling of RNAs in intact mice, finding that mature sperm carry small RNAs that were originally synthesized in the somatic cells of the epididymis. Taken together, our data demonstrates that soma-germline small RNA transfer occurs in male mammals, most likely via vesicular transport from the epididymis to maturing sperm.

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