The Expression of Cold-Inducible RNA-Binding Protein mRNA in Sow Genital Tract Is Modulated by Natural Mating, But Not by Seminal Plasma.

Jaume Gardela,Dominic Wright,Heriberto Rodriguez-Martinez,Manel López-Béjar,Cristina A. Martinez,Mateo Ruiz-Conca,Manuel Alvarez-Rodriguez

doi:10.3390/ijms21155333

Abstract

The RNA-binding proteins (RBPs), some of them induced by transient receptor potential (TRP) ion channels, are crucial regulators of RNA function that can contribute to reproductive pathogenesis, including inflammation and immune dysfunction. This study aimed to reveal the influence of spermatozoa, seminal plasma, or natural mating on mRNA expression of RBPs and TRP ion channels in different segments of the internal genital tract of oestrous, preovulatory sows. Particularly, we focused on mRNA expression changes of the cold-inducible proteins (CIPs) and related TRP channels. Pre-ovulatory sows were naturally mated (NM) or cervically infused with semen (Semen-AI) or sperm-free seminal plasma either from the entire ejaculate (SP-TOTAL) or the sperm-rich fraction (SP-AI). Samples (cervix to infundibulum) were collected by laparotomy under general anaesthesia for transcriptomic analysis (GeneChip® Porcine Gene 1.0 ST Array) 24 h after treatments. The NM treatment induced most of the mRNA expression changes, compared to Semen-AI, SP-AI, and SP-TOTAL treatments including unique significative changes in CIRBP, RBM11, RBM15B, RBMS1, TRPC1, TRPC4, TRPC7, and TRPM8. The findings on the differential mRNA expression on RBPs and TRP ion channels, especially to CIPs and related TRP ion channels, suggest that spermatozoa and seminal plasma differentially modulated both protein families during the preovulatory phase, probably related to a still unknown early signalling mechanism in the sow reproductive tract.

Highlights

Mammals reproduce by internal fertilization releasing billions of spermatozoa into the female reproductive tract to achieve maximum chances of fertilization, despite only thousands reaching the oviduct [1], where fertilization takes place
It seems to be certain that RNA-binding proteins (RBPs) and transient receptor potential (TRP) ion channels are involved in multiple mechanisms during the pre-ovulation phase of the sow; the exact mechanisms produced in the interaction between semen and the female reproductive tract have not yet been elucidated
We identified specific differentially expressed mRNA of genes encoding for cold-inducible proteins (CIPs) and related TRP ion channels along the sow reproductive tract, suggesting that spermatozoa and seminal plasma differentially modulated both protein families during the pre-ovulatory phase

Summary

Introduction

Mammals reproduce by internal fertilization releasing billions of spermatozoa into the female reproductive tract to achieve maximum chances of fertilization, despite only thousands reaching the oviduct [1], where fertilization takes place. Each step of RNA metabolism (transcription, splicing, polyadenylation, stabilization, edition, capping, or translation) is assisted by the RBPs [13] These proteins are the most important regulators of RNAs and crucial for gene regulation, containing different structural RNA-binding motifs or domains, such as RNA recognition motif (RRM), K homology domain, double-stranded RNA binding domain, or zinc fingers, forming ribonucleoprotein complexes by binding double or single-stranded RNA [14]. Beyond their RNA-binding domains, the RBPs hold many structural modules that facilitate protein-protein interactions and catalytic events; thereby, they are incorporated in numerous intracellular processes [14]

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