Rodriguez-Gil, J. E. | Search bioRxiv

bioRxiv2019

Identification of circular RNAs in porcine spermatozoa and their relation to sperm motility

Circular RNAs (circRNAs) are emerging as a novel class of noncoding RNAs which potential role as gene regulators is quickly gaining interest. Although circRNAs have been studied in several tissues and cell types across several animal species, the characterization of the circRNAome in ejaculated sperm remains unexplored. In this study, we profiled the sperm circRNA catalogue in 40 boar samples. A complex population of 1,598 circRNAs was shared in at least 30 samples. The predicted circRNAs presented in general low abundances and were highly tissue-specific. Circa 80% of the circRNAs identified in the boar sperm were reported as novel. We also constructed a circRNA-miRNA interaction network based on experimental and predictive microRNA (miRNA) binding sites. Moreover, we found significant correlation between the abundance of some circRNAs and sperm motility parameters and confirmed two of these correlations by RT-qPCR in 36 samples with extreme sperm quality. Our study provides a thorough characterization of a novel cell type for the circRNA encyclopedia collection and suggests that circRNAs are potential noninvasive biomarkers for male sperm quality and thus, might also hold potential to predict male fertility.

genomics↗

bioRxiv2018

A thorough RNA-seq characterization of the porcine sperm transcriptome and its seasonal changes

Understanding the molecular basis of cell function and ultimate phenotypes is crucial for the development of biological markers. With this aim, several RNA-seq studies have been devoted to characterize the transcriptome of ejaculated spermatozoa in relation to sperm quality and fertility. Semen quality follows a seasonal pattern and decays in the summer months in several animal species. The aim of this study was to deeply profile the transcriptome of the boar sperm and to evaluate its seasonal changes. We sequenced the total and the short fractions of the sperm RNA from 10 Pietrain boars, 5 collected in summer and 5 five sampled in winter, and identified a complex and rich transcriptome with 4,436 coding genes of moderate to high abundance. Transcript fragmentation was high but less obvious in genes related to spermatogenesis, chromatin compaction and fertility. Short non-coding RNAs mostly included piwi-interacting RNAs, transfer RNAs and micro-RNAs. We also compared the transcriptome of the summer and the winter ejaculates and identified 34 coding genes and 7 micro-RNAs with a significantly distinct distribution. These genes were mostly related to oxidative stress, DNA damage and autophagy. This is the deepest characterization of the boar sperm transcriptome and the first study linking the transcriptome and the seasonal variability of semen quality in animals. The annotation described here can be used as a reference for the identification of markers of sperm quality in pigs.

genomics↗