Evolutionary conservation of the mature oocyte proteome

Abstract The proteome profiles of mature ovulated oocytes of the Cnidaria basal eumetazoan, the starlet sea anemone Nematostella vectensis was compared with published data of mammalian mouse mature oocytes. We identified 1837 proteins in N. vectensis oocytes including known oocyte- and germ-cell-specific markers, proteins associated with RNPs and vitellogenin, a major component of egg yolk proteins. Our findings suggest highly conserved enriched functional pathways in N. vectensis and the mouse mature oocytes. This study provides the first catalog of cnidarian oocyte proteins, revealing highly conserved ancient organization of life processes for over 500 million years of evolution. Significance The current study provides the first proteomic profile of an oocyte of a cnidarian organism the starlet sea anemone N. vectensis and gives new insights on the ancient origin of an oocyte proteome template. The comparative analysis with a chordate oocyte suggests that the oocyte proteome predates the divergence of the cnidarian and bilaterian lineages. In addition, the data generated in the study will serve as a valuable resource for further developmental and evolutional studies.