Characterise the ovine spermatozoal transcriptome, and evaluate whether transcriptomic differences correlate with differences in breed or semen quality

The exact extent to which spermatozoal RNA influences conception and embryonic development is not yet known but is hypothesised to influence fertilisation success, embryonic development and offspring phenotype. Semen was collected from merino, dohne and poll dorset rams (n = 48) which were matched for age, management conditions and location. Each ejaculate was assessed utilising a Computer Assisted Semen Analysis (CASA) machine to determine ejaculate quality. RNA was later extracted from each sample, with RNA sequencing analysis occuring, allowing for comparison of spermatozoal gene expression between three key Australian breeds of sheep. It is suspected that spermatozoal RNA transcripts will differ between the three breeds sampled. It is further expected to find transcriptional differences in RNA sequencing, both between breeds and high and low quality ejaculates. This will allow for further understanding of how semen contributes to reproductive outcomes, thereby ensuring accurate and thorough evaluation of male fertility prior to breeding.