Data/hora: 05/06/2024 09:56:29

Provedor de dados: | 5
País: | France
Título: | Adaptation du métabolisme respiratoire de l'huître creuse Crassostrea gigas
Autores: | Le Moullac, Gilles.
Data: | 2008-05-15
Ano: | 2008
Palavras-chave: | Régulation; Enzyme; Expression génique; Anoxie; Bivalve.
Resumo: | Summer mortality of the oyster result from the interaction of many factors. A respiratory assumption proposes a link between the supposed causes of the energy state, the cultivation methods and the medium. This work is focused towards the search for specific metabolic markers of environmental stresses. The cDNA of genes coding for PK and PEPCK were cloned and sequenced in order to detect their regulation level. The sediment nearness affects the state of energy reserves, the metabolic pathways of energy production implying a regulation of the PK. Face to the dissolved oxygen decline, oysters were oxyregulator but with a low regulation ability. In hypoxia, glycolysis was slowed down. PK activity was inhibited resulting from an increase in alanine sensitivity whereas ETS activity of the respiratory chain was stimulated. When exposed to sulphides, filtration of oyster was affected from 20&amp;#956;M whereas the oxygen consumption persisted. At short term, an anaerobic metabolic pathway associated to the inhibition of the respiratory chain and the fall of CEA took place. Muscular PK and PEPCK had different regulation levels: PEPCK appeared controlled at the transcriptional level and PK was first allosterically regulated before to be lately regulated at transcriptional level. Lastly, this study revealed new specificities of the oysters R and S. In normoxia, the more important stock of carbohydrate of the S oysters was correlated to a higher production of ATP via a more intense PK activity. In hypoxia, the expression of the muscular PEPCK was stimulated in S oyster. In all the situations, the oysters R produce more alanine.
Tipo: | Text
Idioma: | Francês
Identificador: | http://archimer.ifremer.fr/doc/2008/these-4315.pdf
Editor: | Université de Caen Basse Normandie
Relação: | http://archimer.ifremer.fr/doc/00000/4315/
Formato: | application/pdf