Glucose overload in yolk has little effects on the long term modulation of carbohydrate metabolic genes in zebrafish (Danio rerio)
- Authors
- Rocha, F., Dias, J., Engrola, S., Gavaia, P., Geurden, I., Dinis, M.T., and Panserat, S.
- ID
- ZDB-PUB-140220-28
- Date
- 2014
- Source
- The Journal of experimental biology 217(Pt 7): 1139-49 (Journal)
- Registered Authors
- Keywords
- none
- MeSH Terms
-
- Animals
- Carbohydrate Metabolism*
- Dietary Carbohydrates
- Egg Yolk/metabolism
- Embryo, Nonmammalian/physiology*
- Gene Expression
- Glucose/metabolism
- Larva
- Zebrafish/embryology*
- Zebrafish/genetics*
- Zebrafish/metabolism*
- PubMed
- 24363414 Full text @ J. Exp. Biol.
Some fish show a low metabolic ability to use dietary carbohydrates. The use of early nutritional stimuli to program metabolic pathways in fish is ill defined. Studies were undertaken with zebrafish to assess the effect of high glucose levels during embryonic stage as lifelong modulator of genes involved in carbohydrate metabolism. Genes related to carbohydrate metabolism showed low expression levels at 0.2 and 1 days post-fertilization (dpf). However, from 4 dpf onwards there was a significant increase on expression of all genes, suggesting that all analysed pathways were active. By microinjection, we successfully enriched zebrafish egg yolk with glucose (a 43-fold increase of basal levels). Acute effects of glucose injection on gene expression were assessed in larvae up to 10 dpf, while the programming concept was evaluated in juveniles (41 dpf) challenged with a hyperglucidic diet. At 4 dpf, larvae from glucose-enriched eggs showed a down-regulation of several genes related to glycolysis, glycogenolysis, lipogenesis and carbohydrate digestion in comparison with control (saline injected). This inhibitory regulation was suppressed after 10 dpf. At the juvenile stage and upon switching from a low to a high digestible carbohydrate diet, early glucose enrichment had no significant effect on most analysed genes. Still, these same fish showed altered expression of PEPCKc, SGLT1 and GS genes, suggesting changes on glucose storage capacity in muscle and glucose production and transport in viscera. On the overall, egg yolk supplementation with high glucose levels had little effects on the long term modulation of carbohydrate metabolic genes in zebrafish.