Abstract
The aim of this study was to establish a fasting-refeeding protocol to investigate the expression of growth-related genes during the transition between catabolic and anabolic states in Atlantic halibut (Hippoglossus hippoglossus L). Juveniles of similar to 950 g were maintained at ambient temperature (5-8 degrees C) until the 1st of May, then fasted for two months and refed for two months at 7.7-8.0 degrees C under continuous low light. Fast epaxial myotomal muscle was sampled at -64 d (days), -38 d, 0 d (start of refeeding), 3 d, 7 d, 14 d, 30 d and 60 d. Average body mass was unchanged over the fasting period but increased by 24.4% following 60 d refeeding. qPCR was used to analyse the stability of expression of five potential reference genes (Eef2, Fau, 18S rRNA, Actb and Tubb2) with GeNorm and Normfinder. Expression of the growth-related genes, cathepsin B (ctsb), cathepsin D (ctsd), insulin-like growth factor-I and II (IGF-I and II) and insulin-like growth factor-I receptor I a (IGF-IRa) was normalised using the geometric average of the two most stable housekeeping genes, Fau and 18S rRNA. IGF-I mRNA showed a transient 2.6-fold increase in abundance with refeeding at 7 d whilst transcripts for IGF-II and lGF-IRa were elevated during fasting and decreased 3.8-fold and 3-fold between the 0 d and 3 d samples respectively. Ctsb expression increased between -64 d and 0 d and then decreased similar to 10-fold by 14 d refeeding. In contrast, ctsd was relatively unaffected by the fasting-refeeding cycle, showing a modest (similar to 35%) transient decrease in expression between the 0 d and 30 d refeeding samples. It was concluded that the experimental protocol adopted and housekeeping genes identified were suitable for investigating the catabolic-anabolic transition in halibut skeletal muscle. (c) 2008 Elsevier Inc. All rights reserved.
Original language | English |
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Pages (from-to) | 47-53 |
Number of pages | 7 |
Journal | Comparative Biochemistry and Physiology - Part B: Biochemistry and Molecular Biology |
Volume | 152 |
Issue number | 1 |
DOIs | |
Publication status | Published - Jan 2009 |
Keywords
- Atlantic halibut
- Cathepsin
- Fasting
- Refeeding
- Reference gene
- IGF
- MESSENGER-RNA EXPRESSION
- BASS DICENTRARCHUS-LABRAX
- COD GADUS-MORHUA
- COMPENSATORY GROWTH
- SKELETAL-MUSCLE
- FACTOR-I
- IGF-II
- LYSOSOMAL-ENZYME
- INSULIN
- STARVATION