title: Complexity of Yolk Proteins and Their Dynamics in the Sea Star Patiria miniata.
abstract: Oviparous animals store yolk proteins within the developing oocyte. These proteins are used in gametogenesis and as a nutritional source for embryogenesis. Vitellogenin and the major yolk protein are two of the most important yolk proteins among diverse species of invertebrates and vertebrates. Among the echinoderms, members of the subphyla Echinozoa (sea urchins and sea cucumbers) express the major yolk protein (MYP) but not vitellogenin (Vtg), while an initial report has documented that two Asterozoa (sea stars) express a vitellogenin. Our results show that sea stars contain two vitellogenins, Vtg 1 and Vtg 2, and MYP. In Patiria miniata, these genes are differentially expressed in the somatic and germ cells of the ovary: Vtg 1 is enriched in the somatic cells of the ovary but not in the oocytes, and Vtg 2 accumulates in both oocytes and somatic cells; MYP is not robustly present in either. Remarkably, Vtg 2 and MYP mRNA reappear in larvae; Vtg 2 is detected within cells of the ectoderm, and MYP accumulates in the coelomic pouches, the intestine, and the posterior enterocoel (PE), the site of germ line formation in this animal. Additionally, the Vtg 2 protein is present in oocytes, follicle cells, and developing embryos, but becomes undetectable following gastrulation. These results help elucidate the mechanisms involved in yolk dynamics, and provide molecular information that allows for greater understanding of the evolution of these important gene products.
authors.affiliation: Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, 185 Meeting Street, Box G-SFH, Providence, Rhode Island 02912; and.
authors.forename: Vanesa
authors.initials: V
authors.lastname: Zazueta-Novoa
authors.affiliation: Department of Natural Sciences, LaGuardia Community College/CUNY, Room M207, 31-10 Thomson Avenue, Long Island City, New York 11101 rhet@brown.edu.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Onorato
authors.affiliation: Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, 185 Meeting Street, Box G-SFH, Providence, Rhode Island 02912; and Department of Natural Sciences, LaGuardia Community College/CUNY, Room M207, 31-10 Thomson Avenue, Long Island City, New York 11101.
authors.forename: Gerardo
authors.initials: G
authors.lastname: Reyes
authors.affiliation: Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, 185 Meeting Street, Box G-SFH, Providence, Rhode Island 02912; and.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Oulhen
authors.affiliation: Department of Molecular Biology, Cellular Biology and Biochemistry, Brown University, 185 Meeting Street, Box G-SFH, Providence, Rhode Island 02912; and rhet@brown.edu.
authors.forename: Gary M
authors.initials: GM
authors.lastname: Wessel
mesh_terms: D000818:Animals; D004447:Echinodermata / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004527:Egg Proteins / Q000032:analysis / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D005260:Female; D018507:Gene Expression Regulation, Developmental; D010053:Ovary / Q000378:metabolism
chemical_list: D004527:Egg Proteins