Epididymal transcriptional networks underlying sperm motility differences in Chinese indigenous chicken breeds

This study characterized phenotypic distinctions between high- and low-motility sperm from 40-week-old Yufen1 roosters and the alteration in epididymal transcriptional networks underlighting sperm motility. Temperature challenge tests (4 °C and 37 °C) revealed that high-viability sperm maintained significantly better survival rates at both temperatures compared to low-viability samples, and high-motility sperm consistently exhibited lower morphological abnormality rates across temperature conditions (P < 0.05), which was further confirmed by extended fertilization windows (P < 0.05) and produced more fertilized eggs (P < 0.05) compared to the low-motility group. Transcriptomic analysis of the epididymis showed 723 differentially expressed genes between the low- and high- motility groups, with functional enrichment indicating significant alterations in lipid metabolism pathways and ATP synthesis-related processes. Accordingly, genes related to fat deposition such as acyl-CoA synthetase bubblegum family member 1 (ACSBG1), glycerate kinase (GLYCTK), and CDP-diacylglycerol synthase 1 (CDS1) were downregulated (all P < 0.05), whereas the mRNA level of β-oxidation gene acyl-coenzyme A thioesterase 6 (ACOT6) was increased (P < 0.05) in the high motility group as compared to the low motility group. In addition, when compared to the low motility group, the high motility semen exhibited decreased levels of both reactive oxygen species (ROS) and malondialdehyde in seminal plasma (both P < 0.05). In conclusion, the maintenance of sperm motility is associated with lipid metabolism remodeling, where these metabolic adaptations enhance ATP production while simultaneously reducing ROS generation in Yufen1 roosters.