Glucose metabolic gene expression in growth hormone transgenic coho salmon.
Salmonids are generally known to be glucose intolerant. However, previous studies have shown that growth hormone (GH) transgenic coho salmon display modified nutritional regulation of glycolysis and lipogenesis compared to non-transgenic fish, suggesting the potential for better use of glucose in GH transgenic fish. To examine this in detail, GH transgenic and non-transgenic coho salmon were subjected to glucose tolerance test and subsequent metabolic assessments. After intra-peritoneal injection of 250mg/kg glucose, we analysed post-injection kinetics of glycaemia and expression of several key target genes highly involved in glucose homeostasis in muscle and liver tissues. Our data show no significant differences in plasma glucose levels during peak hyperglycaemia (3-6h after injection), demonstrating a similar glucose tolerance between transgenic and non transgenic. However, and unrelated to the hyperglycaemic episode, GH transgenic fish return to a slightly lower basal glycaemia values 24h after injection. Correspondingly, GH transgenic fish exhibited higher mRNA levels of glucokinase (GK) and glucose-6-phosphate dehydrogenase (G6PDH) in liver, and glucose transporter (GLUT4) in muscle. These data suggest that these metabolic actors may be involved in different glucose use in GH transgenic fish, which would be expected to influence the glucose challenge response. Overall, our data demonstrate that GH transgenic coho salmon may be a pertinent animal model for further study of glucose metabolism in carnivorous fish.
INRA, UR1067 Nutrition Metabolism and Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France. Electronic address: panserat@st-pee.inra.fr.
Stéphane
S
Panserat
INRA, UR1067 Nutrition Metabolism and Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France.
Biju Sam
BS
Kamalam
INRA, UR1067 Nutrition Metabolism and Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France.
Jeanne
J
Fournier
INRA, UR1067 Nutrition Metabolism and Aquaculture, Aquapôle, F-64310 Saint-Pée-sur-Nivelle, France.
Elisabeth
E
Plagnes-Juan
Fisheries and Oceans Canada, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, BC V7V 1N6, Canada.
Krista
K
Woodward
Fisheries and Oceans Canada, Centre for Aquaculture and Environmental Research, 4160 Marine Drive, West Vancouver, BC V7V 1N6, Canada.
Robert H
RH
Devlin
D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics*; D005786:Gene Expression Regulation; D005941:Glucokinase / Q000096:biosynthesis; D005947:Glucose / Q000378:metabolism*; D051275:Glucose Transporter Type 4 / Q000096:biosynthesis; D005954:Glucosephosphate Dehydrogenase / Q000096:biosynthesis; D013006:Growth Hormone / Q000096:biosynthesis / Q000235:genetics*; D008099:Liver / Q000201:enzymology; D009132:Muscles / Q000201:enzymology; D017684:Oncorhynchus kisutch / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis
D051275:Glucose Transporter Type 4; D012333:RNA, Messenger; D013006:Growth Hormone; D005954:Glucosephosphate Dehydrogenase; D005941:Glucokinase; D005947:Glucose
Glucose metabolism; Growth hormone; Salmon; Transgenic fish