Metabolomic fingerprinting of bull spermatozoa for identification of fertility signature metabolites

Abstract

The objective of the study was to identify the fertility‐associated metabolites in bovine spermatozoa using liquid chromatography‐mass spectrometry (LC‐MS). Six Holstein Friesian crossbred bulls (three high‐fertile and three low‐fertile bulls) were the experimental animals. Sperm proteins were isolated and protein‐normalized samples were processed for metabolite extraction and subjected to LC‐MS/MS analysis. Mass spectrometry data were processed using iMETQ software and metabolites were identified using Human Metabolome DataBase while, Metaboanalyst 4.0 tool was used for statistical and pathway analysis. A total of 3,704 metabolites belonging to various chemical classes were identified in bull spermatozoa. After sorting out exogenous metabolites, 56 metabolites were observed common to both the groups while 44 and 35 metabolites were found unique to high‐ and low‐fertile spermatozoa, respectively. Among the common metabolites, concentrations of 19 metabolites were higher in high‐fertile compared to low‐fertile spermatozoa (fold change > 1.00). Spermatozoa metabolites with variable importance in projections score of more than 1.5 included hypotaurine, d‐cysteine, selenocystine. In addition, metabolites such as spermine and l‐cysteine were identified exclusively in high‐fertile spermatozoa. Collectively, the present study established the metabolic profile of bovine spermatozoa and identified the metabolomic differences between spermatozoa from high‐ and low‐fertile bulls. Among the sperm metabolites, hypotaurine, selenocysteine, l‐malic acid, d‐cysteine, and chondroitin 4‐sulfate hold the potential to be recognized as fertility‐associated metabolites.

Metabolomic fingerprinting of pig seminal plasma identifies in vivo fertility biomarkers

“…With regard to sperm, the addition of hypotaurine to cryopreservation media has been reported to exert a positive effect on sperm quality and functionality parameters in sheep 55 and humans 54,56 . In addition, sperm from bulls with high fertility records also have high hypotaurine levels 57 . While, considering all this evidence, one could surmise that SP-hypotaurine has a positive impact on pig sperm physiology, further studies are required to con rm this hypothesis.…”

Cellular and Molecular Insights Into the Etiology of Subfertility/Infertility in Crossbred Bulls (Bos taurus × Bos indicus): A Review

“…Recent studies profiled sperm RNA and the possible roles in sperm functions and fertilizing ability ( Selvaraju et al, 2017 ; Paul et al, 2020 ; Prakash et al, 2020 ). Increasing evidence indicates that expression of sperm molecules, including mRNAs ( Wang et al, 2019 ; Saraf et al, 2021 ; Selvaraju et al, 2021 ), proteins ( Peddinti et al, 2008 ; Aslam et al, 2015 ), phosphoproteins ( Kumaresan et al, 2012 ), and metabolites ( Saraf et al, 2020 ), were altered in bulls with different fertility ratings. All these molecules reflect sperm health and correlate with their fertilizing ability.…”

“…Although several studies have examined metabolites in human spermatozoa, few studies are available on bull spermatozoa. Recently, metabolites in spermatozoa from high fertility and low fertility crossbred bulls were studied using LC-MS/MS analysis; hypotaurine, L-malic acid, selenocysteine, D-cysteine, and chondroitin 4-sulfate could be markers for crossbred bull fertility ( Saraf et al, 2020 ). Similarly, in a study conducted to assess the sperm metabolomic differences between purebred and crossbred cattle, 1,732 and 1,240 metabolites were identified in purebred and crossbred bull spermatozoa, respectively.…”

Comparative Transcriptomic Analysis of Spermatozoa From High- and Low-Fertile Crossbred Bulls: Implications for Fertility Prediction

“…Reportedly, a greater proportion of crossbred bulls were culled due to infertility/subfertility and poor semen quality; the average ejaculate rejection rate was around 55% in crossbred bulls ( Tyagi et al, 2000 ; Mukhopadhyay et al, 2010 ; Vijetha et al, 2014a , b ). Therefore, our team has been working toward the aim of decoding the reason behind infertility/subfertility in crossbred bulls, and we found the differences in the proportion of Sertoli cells ( Tripathi et al, 2015 ), metabolomic profile of spermatozoa ( Saraf et al, 2020 ), proteomic profile of seminal plasma ( Aslam et al, 2014 ), spermatozoa ( Aslam et al, 2015 ), spermatogenic and Sertoli cells ( Tripathi et al, 2014 ), and transcriptomic details of testicular tissue ( Elango et al, 2020 ) between crossbred and purebred cattle. However, transcriptomics of crossbred bull sperm is underexplored, although recent studies revealed the relationship of sperm transcripts with sperm function and fertility of purebred bulls ( Card et al, 2017 ; Ren et al, 2017 ; Burl et al, 2018 ; Dhawan et al, 2018 ).…”