Teleost fishes are a highly diverse and ecologically essential group of
aquatic vertebrates and include coho salmon, Onchorhynchus kisutch. Coho
are semelparous and all ovarian follicles develop synchronously. Owing
to their ubiquitous distribution, teleost provide critical sources of
food worldwide through subsistence, commercial fisheries, and
aquaculture. Enhancement of commercial hatchery practices requires a
detailed knowledge of teleost reproductive physiology. Despite decades
of research on teleost reproductive processes, an in-depth proteome of
teleost ovarian development has yet to be generated. We describe a coho
salmon ovarian proteome of over 5700 proteins, generated with data
independent acquisition, revealing the suite of detectable proteins that
change through the transition from primary to secondary ovarian follicle
development. This transition is critical for puberty onset, egg quality,
and further embryonic development. Primary ovarian follicle development
was marked by differential abundances of proteins involved in
carbohydrate metabolism, protein turnover, and the complement pathway,
suggesting elevated metabolism as the oocytes enter maturation. The
greatest proteomic shift occurred during the transition from primary to
secondary follicle growth, with increased abundance of proteins
underlying cortical alveoli formation, extracellular matrix
reorganization, iron binding, and cell-cell signaling. This work
provides a foundation for identifying biomarkers of salmon oocyte stage
and quality.