Beneficial effects of relaxin on motility characteristics of stored boar spermatozoa

Abstract

BackgroundRelaxin is detected in seminal plasma of many species and its association with sperm motility may be beneficial in some aspects of assisted reproduction. Here, we immunolocalized relaxin receptors and investigated the effects of exogenous relaxin on motility characteristics, viability, and cAMP content of boar spermatozoa after storage.MethodsCommercial doses of boar semen were obtained on the collection day (Day 0) and kept in shipping containers at room temperature for up to 4 days (Day 4). On Day 0, spermatozoa were fixed for immunofluorescence detection of relaxin receptors RXFP1 and RXFP2 (Experiment 1). Semen aliquots were taken from the same dose at Day 0, Day 1, and Day 2 (Experiment 2a), and Day 2 and Day 4 (Experiment 2b) for analyses. Alive spermatozoa were purified and incubated (1 h-37°C) with 0, 50, or 100 ng relaxin/ml (Experiment 2a) and 0, 100, or 500 ng relaxin/ml (Experiment 2b). Afterward, aliquots of each treatment group were subjected to motility (Experiments 2), viability (Experiment 3) analyses, and cAMP quantification (Experiment 4). Data (3–4 independent replicates) were statistically analyzed (ANOVA followed by pairwise comparisons) and p values less or equal to 0.05 was set for significant difference.ResultsBoth RXFP1 and RXFP2 receptors were immunolocalized on the entire spermatozoon. Relaxin concentration of 100 ng/ml significantly improved the proportions of motile, progressive, and rapid spermatozoa up to Day 2. Only 500 ng relaxin/ml provided beneficial effects on Day 4. The viability of spermatozoa was not affected by relaxin (100 ng/ml) during storage, but the extent of mitochondria membrane damages was significantly decreased. Furthermore, relaxin did not affect the cAMP contents of spermatozoa during storage, in our conditions.ConclusionsRelaxin could be a valuable motility booster of stored- or aged-spermatozoa for assisted reproduction techniques. However, the related-intracellular signaling cascades of relaxin in boar spermatozoa remain undetermined.Electronic supplementary materialThe online version of this article (doi:10.1186/s12958-015-0021-4) contains supplementary material, which is available to authorized users.

Functional insulin‐like factor 3 (INSL3) hormone‐receptor system in the testes and spermatozoa of domestic ruminants and its potential as a predictor of sire fertility

“…) and its protein is distributed throughout the entire spermatozoon in boars (Feugang et al . ). However, the reason for discrepancy in receptor distribution is unclear, but it might be due to differences in animal species and antibodies used.…”

Self-illuminating quantum dots for non-invasive bioluminescence imaging of mammalian gametes

“…Laser fluorescence imaging was performed with the confocal microscope (LSM510, Carl Zeiss Micro Imaging GmbH, Jena, Germany). For direct imaging, anti-human plasminogen antibody (Santa Cruz Biotechnology) was used for in situ immunofluorescence detection using FITC-conjugated secondary antibody as previously described [ 27 ]. After mounting on microscope histology slides with medium containing DAPI to counterstain nuclei, slides were used for confocal fluorescence imaging.…”

Recent Advances in Research on the Hormone INSL3 in Male Goats

“…Furthermore, we investigated the functionality of RXFP2 in these spermatozoa using in situ ligand binding assay with DTBTA-Eu-INSL3 and clearly showed the presence of functional RXFP2 enabling INSL3 to bind with the equatorial segment of he-goat (Figure 10B), bull, and ram spermatozoa, suggesting that a functional INSL3 hormone-receptor system operates in the equatorial segment of ruminant spermatozoa [36]. It has been reported to date that RXFP2 mRNA is detected in the spermatozoa of rats [41] and boars [42] and its protein is distributed throughout the entire spermatozoon in boars [43]. However, the reason for discrepancy in receptor distribution is unclear, but it might be due to differences in animal species and antibodies used.…”