Research Note: Spermatozoa proteins identification in domesticated pigeons by proteomic analysis

Proteins are considered major effectors of sperm function. However, the proteins expressed in pigeon sperm have not been explored. Here, we collected semen from meat and racing pigeons using the electroejaculation method and identified proteins in pigeon sperm using the proteomics approach. A total of 1,641 proteins were identified in the sperm of domesticated pigeons. Of which, 1,541 proteins were reliably quantified, and gene ontology (GO) and associated bioinformatics analyses indicated that annotated proteins were linked to the oxidation-reduction process, integral component membrane, and protein binding, etc. Among quantified proteins, 1,515 and 1,507 proteins were respectively presented in White King pigeons and racing pigeons, and 1,481 proteins were shared between these 2 types of pigeons, including axonemal dynein, solute carrier, cilia- and flagella-associated protein, outer dense fiber protein, etc. Proteins in our constructed protein-protein interaction (PPI) network are involved in oxidative phosphorylation, sperm axoneme assembly, cilium-dependent cell motility, axonemal dynein complex assembly, flagellated sperm motility, etc. In conclusion, this study characterized the sperm proteome of pigeons and provided a foundation for the subsequent research screening markers for fertility evaluation of pigeons.