Potential Proteins Associated with Canine Epididymal Sperm Motility

The maturation and motility of epididymal sperm (ES) cells are largely driven by changes in protein expression. This study aimed to analyze the proteomic profile of canine (<i>Canis lupus familiaris</i>) ES across groups characterized by different progressive motility (PMOT) values to identify motility-related sperm proteins (MRSPs). ES were obtained from the epididymal semen of 19 dogs. The motility and movement parameters of ejaculated sperm (ES) were evaluated using computer-assisted semen analysis (CASA). Samples were classified into two groups: good sperm motility (GSM), defined as PMOT% ≥ 55%, and poor sperm motility (PSM), defined as PMOT < 55%. Principal component analysis (PCA) of the first two components could explain 88.1% of the total variance between the GSM and PSM groups. Protein profiling of ES was performed using NanoUPLC-Q-TOF/MS. Significant statistical differences were demonstrated between the GSM and PSM groups for the TMOT (<i>p</i> = 0.039) and PMOT (<i>p</i> < 0.001). For five common proteins, their abundance was estimated to be higher in the GSM group than in the PSM group: ACTB (<i>p</i> = 0.2732), CRISP2 (<i>p</i> = 0.1558), LTF (<i>p</i> = 0.2661) and significantly higher: ce10 (<i>p</i> = 0.009) and NPC2 (<i>p</i> < 0.0044). These findings may be used to develop diagnostic MRSP-based tests related to ES quality in assisted reproduction techniques in dogs.