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Increasing the level of digestible carbohydrates in aqua-feed formula for carnivorous fish species is of interest to improve the sustainability of salmonid (trout) aquaculture. However, as carnivorous species, trout are poor user of dietary carbohydrates and considered a glucose-intolerant (GI) species. Research efforts directed towards overcoming metabolic bottlenecks in the trout’s poor capacity to utilize carbohydrates have thus increasingly led to better understanding of trout metabolism and its regulation. Indeed, investigations carried out under this theoretical framework since the 1990s have characterized the role of nutritional carbohydrate intake as a modulator of expression of key enzymes of intermediary metabolism and glucose utilization. More recently, it has been discovered that trout fed a high carbohydrate diet display a global hepatic CpG DNA hypomethylation at the genome level, but also at specific CpG sites at two out of five duplicated gluconeogenic gene loci considered to contribute to the GI phenotype by their atypical regulation by dietary carbohydrates. This DNA hypomethylation highlighted in trout mimics the phenotype observed under hyperglycaemic conditions in mammals and zebrafish as well as the phenotype described in diabetes. It is well accepted that DNA hypomethylation can lead to genome instability through modification of expression of both protein coding or miRNA genes. While the modulation of intermediary metabolism-related genes by dietary carbohydrates has been previously studied in detail in rainbow trout, their impact on miRNA remains poorly, if at all, described and understood. Indeed, DNA methylation is known to play an important role in the regulation of miRNA expression. Conversely, the involvement of miRNA in the differential regulation of duplicated gluconeogenic genes in trout has never been explored. The present project aims to specifically investigating these two areas pertaining to miRNA regulation and function in the context of diet-induced hyperglycemia in rainbow trout.
Lucie Marandel started her scientific carrier as an Angineer in agronomy at Agrocampus Ouest in Rennes, France in 2005. In 2008, she obtained her PhD in Biology and epigenetics at the University of Rennes most precisly the Inra Fish Phisiology and genomics lab. In 2012, she became a postdoc researcher and was a part the Initial Training Network INGENIUM thanks to the Marie Curie fellowship in Liège, Belgium. Since 2014 and until now, she is an INRA permanent researcher in the Nutrition Metabolism and Aquacukture lab in Saint-pée-sur Nivelle, France.
Marandel, L., Panserat, S., Plagnes- Juan, E., Arbenoits, E., Soengas, J. L., Bobe, J., 2017. Evolutionary history of glucose-6-phosphatase encoding genes in vertebrate lineages: towards a better understanding of the functions of multiple duplicates. BMC Genomics, 18, 1-13. Doi: 10.1186/s12864-017-3727-1.
Liu, J., Plagnes- Juan, E., Geurden, I., Panserat, S., Marandel, L., 2017. Exposure to an acute hypoxic stimulus during early life affects the expression of glucose metabolism-related genes at first-feeding in trout. Scientific Reports, 7 (1), 1-11.
Liu, J., Dias, K., Plagnes- Juan, E., Veron, V., Panserat, S., Marandel, L., 2017. Long-term programming effect of embryonic hypoxia exposure and high-carbohydrate diet at first feeding on glucose metabolism in juvenile rainbow trout. Journal of Experimental Biology, 220 (20), 3686-3694.
Marandel, L., Lepais, O., Arbenoits, E., Veron, V., Dias, K., Zion, M., Panserat, S., 2016. Remodelling of the hepatic epigenetic landscape of glucose-intolerant rainbow trout (Oncorhynchus mykiss) by nutritional status and dietary carbohydrates. Scientific Reports, 6, 12 p. Doi: 10.1038/ srep32187.
Marandel, L., Seiliez, I., Véron, V., Skiba Cassy, S., Panserat, S., 2015. New insights into the nutritional regulation of gluconeogenesis in carnivorous rainbow trout (Oncorhynchus mykiss): a gene duplication trail. Physiological Genomics, 47 (7), 253-263.