Intake of high levels of vitamin A and polyunsaturated fatty acids during different developmental periods modifies the expression of morphogenesis genes in European sea bass (Dicentrarchus labrax)

Abstract

The effect of the feeding period on larval development was investigated in European sea bass larvae by considering the expression level of some genes involved in morphogenesis. Larvae were fed a control diet except during three different periods (period A: from 8 to 13 d post-hatching (dph); period B: from 13 to 18 dph; period C: from 18 to 23 dph) with two compound diets containing high levels of vitamin A or PUFA. European sea bass morphogenesis was affected by these two dietary nutrients during the early stages of development. The genes involved in morphogenesis could be modulated between 8 and 13 dph, and our results indicated that retinoids and fatty acids influenced two different molecular pathways that in turn implicated two different gene cascades, resulting in two different kinds of malformation. Hypervitaminosis A delayed development, reducing the number of vertebral segments and disturbing bone formation in the cephalic region. These malformations were correlated to an upregulation of retinoic acid receptor g, retinoid X receptor (RXR) a and bone morphogenetic protein (BMP)4. An excess of PUFA accelerated the osteoblast differentiation process through the upregulation of RXRa and BMP4, leading to a supernumerary vertebra. These results suggest that the composition of diets devoted to marine fish larvae has a particularly determining effect before 13 dph on the subsequent development of larvae and juvenile fish.Sea bass larvae: PUFA: Vitamin A: Morphogenesis: Retinoid pathway During the first 3 weeks of life, marine fish larvae undergo major morphological and functional changes to acquire their adult features. From hatching until 7 d post-hatching (dph), the feeding of European sea bass larvae is endogenous. It then becomes mixed until resorption of the vitellus; this generally occurs around 13 dph. At this date, the secretory function of the exocrine pancreas is not fully operational, only becoming efficient around 18 -20 dph. The maturational process of the pancreas is also characterized by a strong decrease in amylase activity between 13 and 20 dph (Zambonino Infante & Cahu, 2001). The maturation of intestinal cells is characterized by a decrease in cytosolic enzyme activity between 18 and 25 dph, whereas the activity of the brush border membrane enzymes increases. During this period of intense functional changes, a huge morphological transformation of the larvae occurs, in particular in the development of the neurocranium and the jaw, the segmentation of the vertebrae that becomes visible around 20 dph, and the settlement of the adult fins between day 27 and day 40 (Barnabé et al. 1976).During the first weeks of development, the maturation processes of the gastrointestinal tract can be influenced by nutritional conditions. Several studies have recently demonstrated that the morphogenesis of marine fish larvae could be perturbed by inappropriate dietary levels of vitamin A (retinol; Haga et al. 2002;Villeneuve et al. 2005a) or PUFA (Cahu et al. 2003). Moreover, the induced skeletal malformations dep...

Gene Expression Patterns During the Larval Development of European Sea Bass (Dicentrarchus Labrax) by Microarray Analysis

“…Amplifications were performed from RNA samples used for microarray analysis. Reverse transcription and real time PCR were monitored as previously described (Villeneuve et al, 2006) using the MyIQ single color real time PCR detection system (Biorad). Reverse transcription products were diluted to 1/300, and 5 μl were used for each real-time PCR reaction.…”

Growth, survival and bone alterations in <italic>Piaractus mesopotamicus</italic> larvae under different rearing protocols

“…HERNÁNDEZ et al (2013) reported variations in the number of vertebrae in Rhamdia quelen larvae from different biotypes reared under laboratory conditions. Also, VILLENUEVE et al (2006) observed a high incidence of supernumerary vertebrae in D. labrax larvae fed with excess of fatty acids in the diet. The high variability in meristic features found in farmed fish can be attributed to the interaction between genetic and environmental factors (BOGLIONE et al, 2001;KOUMOUNDOUROS et al, 2001, HERNÁNDEZ et al, 2013.…”

Crecimiento, supervivencia e incidencia de malformaciones oseas en distintos biotipos de Rhamdia quelen durante la larvicultura

“…Trabajos previos demostraron que diferentes componentes alimenticios pueden desencadenar trastornos en los procesos de desarrollo y diferenciación celular (Cahu et al, 2003;Lall & Lewis-McCrea, 2007). La utilización de vitamina A (Villeneuve et al, 2006;Fernández et al, 2008;Mazurais et al, 2009), vitamina C (Merchie et al, 1997;Wang et al, 2002;Darias et al, 2011) y vitamina D (Darias et al, 2010), entre otras, tienen una marcada relación con los niveles dietarios y la incidencia de malformaciones en las larvas. Sin embargo, estas sustancias se suministran a niveles superiores a los requeridos por las larvas (NRC, 1993), con la finalidad de compensar la pérdida de estos compuestos durante la fabricación de los alimentos o por la rápida lixiviación (principalmente en vitaminas hidrosolubles) (Lazo, 2000;Guillaume et al, 2004).…”