Identification of significantly expressed up and down regulated genes in categorised crossbred bulls

Abstract

Fertility issues and sperm abnormalities can be associated with RNAs found in bovine ejaculates. Currently, bull fertility cannot be fully predicted by the quality parameters that are regularly utilized for semen evaluation. Therefore, the uncertain and questionable predictability of the currently available semen diagnostic procedures encouraged us to search for a sperm transcript-based method for crossbred bull fertility prediction. Keeping in view the importance of transcriptome profiling of bull spermatozoa between high and low fertile Frieswal bulls and their correlation with fertility, the proposed study was designed to generate the spermatozoal transcriptomics profiles of Up and down regulated genes categorised crossbred bulls. The study was carried out at ICAR - CIRC, Meerut Cantt (UP), India; a unit of ICAR-AICRP on Cattle. The RNA-Seq profiling results revealed transcripts for 23,987 genes; of which 498 transcripts were significantly differed (log2 FC±2, p-value < 0.05) between high and low fertile crossbred bull spermatozoa. Out of these 498 genes, 227 transcripts were significantly upregulated (fold change > 2) and 271 were significantly downregulated (fold change < 2) between these groups. Furthermore, identifying the fertility related genes that are specific to these groups can help to discover the potential marker for selection of superior bulls for semen quality traits. Since the study is limited by the small sample sizes, larger sample sizes can be preferred for future validation investigations.