Data/hora: 03/06/2024 11:37:01

Provedor de dados: | 5
País: | France
Título: | Etude des voies metaboliques des sucres chez l'huitre creuse crassostrea gigas. Implication dans les mortalites estivales.
Autores: | Bacca, Helene.
Data: | 2007-11-08
Ano: | 2007
Resumo: | Glycogen, the main form of glucose reserve in bivalves, is known to play a key energetic role in the Pacific oyster (Crassostrea gigas) annual reproduction cycle. The aim of this work was to study the pathways of glycogen synthesis and utilization in order to explain the relationships between energy, reproduction and oyster summer mortality events. We first characterized full length mRNA sequences of Glycogen synthase (Cg-GYS) and Glycogen phosphorylase (Cg-GPH). Biochemical determination of enzymatic activities and adjustment of a RNA absolute quantification method allowed us to study several regulation levels for both markers. Quantities of Cg-GYS and Cg-GPH mRNAs showed seasonal variations, with opposite maximum periods, corresponding to glycogen accumulation or utilization. However, no difference was detected in the enzymatic activities of Glycogen synthase (GS) and Glycogen phosphorylase (GP), thus suggesting that several levels of regulation may exist in the control of C. gigas glycogen metabolism. Moreover, glycogen synthesis was up regulated in vivo by increasing algal diet but neither glucose nor porcine insulin had any effect in vitro on GS and GP activities. Finally, in contribution to the French project MOREST (C.gigas summer mortality), we extended this work by analyzing mRNAs quantities and enzymatic activities of several elements involved in the glucose metabolism. Oysters genetically selected for Resistance (R) or Susceptibility (S) to summer mortality may have different strategies of glucose utilization. The potential energetic advantage of R oyster compared to S oyster is discussed.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/2007/these-3333.pdf
Editor: | Université de RENNES I
Relação: | http://archimer.ifremer.fr/doc/00000/3333/
Formato: | application/pdf