Computer-assisted sperm analysis was conducted to phenotypically and genetically assess the sperm motility traits of Jinding drakes. The phenotypic evaluation revealed moderate variability across motility parameters, consistent with a polygenic inheritance pattern. Correlation analysis further demonstrated strong associations among velocity-related traits and inverse relationships between linearity and lateral head displacement metrics. Genome-wide association studies identified 15 significant single-nucleotide polymorphisms (SNPs) associated with five key sperm motility traits (straight-line velocity, curvilinear velocity, average path velocity, amplitude of lateral head displacement, and mean angular displacement) at a genome-wide threshold of p < 1 × 10−6. Notably, of these 15 SNPs, nine were concentrated on chromosome 1, indicating the presence of a genomic hotspot for regulation of sperm motility. Pleiotropic effects were evident, as several SNPs were found to influence multiple motility traits. Candidate genes implicated in essential sperm functions included Myo16 (cytoskeletal dynamics), Cep76 (flagellar structure), and Jarid2 (epigenetic regulation during spermatogenesis), as well as genes involved in membrane integrity, mitochondrial function, and immune regulation. These findings provide novel insights into the genetic architecture underlying sperm motility of Jinding drakes and establish a basis for molecular breeding strategies to enhance reproductive efficiency of waterfowl.
Zhu et al. (Mon,) studied this question.