Abstract
The present study aims to investigate nutritional programming through early starvation in the European seabass (Dicentrarchus labrax). European seabass larvae were fasted at three different developmental periods for three durations from 60 to 65 dph (F1) ; 81 to 87 dph (F2) and 123 to 133 dph (F3). Immediate effects were investigated by studying gene expression of npy (neuropeptide Y) and avt (Arginine vasotocin) in the head, while potential long term effects (i.e. programming) were evaluated on intermediary metabolism later in life (in juveniles). Our findings indicate a direct effect regarding gene expression in the head only for F1, with higher avt mRNA level in fasted larved compared to controls. The early starvation periods had no long-term effect on growth performance (body weight and body length). Regarding intermediary metabolism, we analysed related key plasma metabolites which reflect the intermediary metabolism: no differences for glucose, triglycerides, and free fatty acids in the plasma were observed in juveniles irrespective of the 3 early starvation stimuli. As programming is mainly linked to molecular mechanisms, we then studied hepatic mRNA levels for 23 key actors of glucose, lipid, amino acid and energy metabolism. For many of the metabolic genes, there was no impact of early starvation in juveniles, except for 3 genes involved in glucose metabolism (glut2-glucose transporter and pk-pyruvate kinase) and lipid metabolism (acly-ATP citrate lyase) which were higher in F2 compared to control. Together, these results highlight that starvation between 81 to 87 dph may have more long term impact, suggesting the existence of a developmental window for programming by starvation. In conclusion, European seabass appeared to be resilient to early starvation during larvae stages without drastic impacts on intermediary metabolism later in life.