Co-expression and regulation of ovarian vitellogenins in the Pacific oyster Crassostrea gigas

• Published in: Aquaculture Research
• Main Authors: Llera-Herrera, Raúl, Vasquez-Boucard, C., García-Gasca, A., Huvet, Arnaud
• Other Authors: Centro de Investigaciones Biológicas del Noroeste (CIBNOR), centro de Investigaciones Biologicas Del Noroeste, Centro de Investigación en Alimentación y Desarrollo (CIAD), Consejo Nacional de Ciencia y Tecnología Mexico (CONACYT), Laboratoire des Sciences de l'Environnement Marin (LEMAR) (LEMAR), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2014
• Subjects: ACL; oogenesis; yolk proteins; follicle cells; vitellogenin; mRNA expression; Pacific oyster; [SDE]Environmental Sciences; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Pacific; Crassostrea gigas
• Online Access: https://hal.univ-brest.fr/hal-00789373; https://doi.org/10.1111/j.1365-2109.2012.03246.x

International audience In addition to the reported single cDNA sequence encoding vitellogenin in the Pacific oyster Crassostrea gigas (referred as Cg-Vtg1), we isolated and characterized the 3′ end of a novel vitellogenin (Vtg) in C. gigas, named Cg-Vtg2. The transcript size is up to 6 kb long and includes a D-type von Willebrand domain, characteristic of most vitellogenins, but not occurring in Cg-Vtg1. The expression of Cg-Vtg2 was found restricted to follicular cells in maturing and ripe female gonads. Quantitative expression analysis of both vitellogenins showed a closely correlated transcription pattern during the female gametogenic cycle, with the highest expression during the ripe (mature) stage, and a declining expression, to almost undetectable levels, in post-spawning (resting) stage. Levels of vitellogenin mRNA associates with the quantity of ingested food. Mature female oysters fed either a 2% or a 12% algal biomass per female biomass, showed a 2.9-fold increase in expression of Cg-Vtg1 and a 3.7-fold increase of Cg-Vtg2 expression levels in those females fed the higher level of algae, suggesting that Vtg's could be used as quantitative indicator of vitellogenesis. Our results suggest that vitellogenins are synthesized during the late period of vitellogenesis, when most of the yolk has already been incorporated into maturing oocytes.