KEGG pathways enrichment of DEPs
KEGG analysis was used to identify the significant functional pathways enriched with differentially expressed proteins. Of the DEPs we obtained 9 significant KEGG pathways (FDR < 0.1; Table 1). These DEPs were mainly classified into oocyte meiosis, nucleotide excision repair, ErbB signaling pathway, gap junction, GnRH signaling pathway, vascular smooth muscle contraction, RNA transport, protein processing in endoplasmic reticulum (FDR < 0.05), and other pathways related to metabolic processes (FDR < 0.1). Among all the DEPs, the GnRH signaling pathway, and the protein processing pathway were most strongly related to the known difference in seasonal reproductive timing in resident and migrant juncos.