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Coordinated gene expression during gilthead sea bream skeletogenesis and its disruption by nutritional hypervitaminosis A.

Fernández I, Darias M, Andree KB, Mazurais D, Zambonino-Infante JL, Gisbert E - BMC Dev. Biol. (2011)

Bottom Line: Present data reflects the specific gene expression patterns of several genes involved in larval fish RA signalling and skeletogenesis; and how specific gene disruption induced by a nutritional VA imbalance underlie the skeletal deformities.Our results are of basic interest for fish VA signalling and point out some of the potential molecular players involved in fish skeletogenesis.Increased incidences of skeletal deformities in gilthead sea bream fed with hypervitaminosis A were the likely ultimate consequence of specific gene expression disruption at critical development stages.

View Article: PubMed Central - HTML - PubMed

Affiliation: Unitat de Cultius Experimentals, IRTA Centre de Sant Carles de la Ràpita (IRTA-SCR), Crta, del Poble Nou s/n, 43540 - Sant Carles de la Ràpita (Spain) ignacio.fernandez@irta.es

ABSTRACT

Background: Vitamin A (VA) has a key role in vertebrate morphogenesis, determining body patterning and growth through the control of cell proliferation and differentiation processes. VA regulates primary molecular pathways of those processes by the binding of its active metabolite (retinoic acid) to two types of specific nuclear receptors: retinoic acid receptors (RARs) and retinoid X receptors (RXRs), which promote transcription of downstream target genes. This process is well known in most of higher vertebrates; however, scarce information is available regarding fishes. Therefore, in order to gain further knowledge of fish larval development and its disruption by nutritional VA imbalance, the relative expression of some RARs and RXRs, as well as several genes involved in morpho- and skeletogenesis such as peroxisome proliferator-activated receptors (PPARA, PPARB and PPARG); retinol-binding protein (RBP); insulin-like growth factors I and II (IGF1 and IGF2, respectively); bone morphogenetic protein 2 (Bmp2); transforming growth factor β-1 (TGFB1); and genes encoding different extracellular matrix (ECM) proteins such as matrix Gla protein (mgp), osteocalcin (bglap), osteopontin (SPP1), secreted protein acidic and rich in cysteine (SPARC) and type I collagen α1 chain (COL1A1) have been studied in gilthead sea bream.

Results: During gilthead sea bream larval development, specific expression profiles for each gene were tightly regulated during fish morphogenesis and correlated with specific morphogenetic events and tissue development. Dietary hypervitaminosis A during early larval development disrupted the normal gene expression profile for genes involved in RA signalling (RARA), VA homeostasis (RBP) and several genes encoding ECM proteins that are linked to skeletogenesis, such as bglap and mgp.

Conclusions: Present data reflects the specific gene expression patterns of several genes involved in larval fish RA signalling and skeletogenesis; and how specific gene disruption induced by a nutritional VA imbalance underlie the skeletal deformities. Our results are of basic interest for fish VA signalling and point out some of the potential molecular players involved in fish skeletogenesis. Increased incidences of skeletal deformities in gilthead sea bream fed with hypervitaminosis A were the likely ultimate consequence of specific gene expression disruption at critical development stages.

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Relative gene expression of RARA, RARB, RXRB and RBP(a), PPARA, PPARB and PPARG (b), Bmp2, TGFB1, IGF1 and IGF2 (c) and mgp, bglap, SPP1, SPARC and COL1A1 (d) in fishes fed with experimental diets (1.5×VA and 10×VA, 1.00*108 and 6.82*108 total VA IU kg-1 DW, respectively) at 18 and 60 dph. Relative gene expression measured as the fold change of the target gene with respect to the house-keeping gene (EF1α) at the appropriate sample time and compared with gene expression in the control group using REST 2008 software. Gene up- and down-regulations are highlighted in red and green (respectively), using different colour tone to identify each experimental group and sampled time. Only significantly higher or lower overall gene expression levels are represented (P < 0.05; n = 3 per dietary group).
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Figure 8: Relative gene expression of RARA, RARB, RXRB and RBP(a), PPARA, PPARB and PPARG (b), Bmp2, TGFB1, IGF1 and IGF2 (c) and mgp, bglap, SPP1, SPARC and COL1A1 (d) in fishes fed with experimental diets (1.5×VA and 10×VA, 1.00*108 and 6.82*108 total VA IU kg-1 DW, respectively) at 18 and 60 dph. Relative gene expression measured as the fold change of the target gene with respect to the house-keeping gene (EF1α) at the appropriate sample time and compared with gene expression in the control group using REST 2008 software. Gene up- and down-regulations are highlighted in red and green (respectively), using different colour tone to identify each experimental group and sampled time. Only significantly higher or lower overall gene expression levels are represented (P < 0.05; n = 3 per dietary group).

Mentions: Regarding RA nuclear receptors, RARA presented at 18 dph a significant up-regulation (1.6 fold change respect to the control group) in 10×VA larvae with respect to control fishes (REST, P < 0.05; Figure 8a); however no significant up- or down-regulation of RARA was found at 60 dph regardless of the dietary conditions (REST, P > 0.05; Figure 8a). In contrast, while no differences in RARG mean gene expression ratio were found at 18 dph in larvae fed with increased dietary VA content (1.5×VA and 10×VA), a slight but significant RARG down-regulation (1.2 and 1.32 fold change, respectively) was found with respect to control larvae at 60 dph (REST, P < 0.05; Figure 8a). Interestingly, no change in gene expression was found concerning the gene RXRB at both sample times analyzed (REST, P > 0.05; Figure 8a).


Coordinated gene expression during gilthead sea bream skeletogenesis and its disruption by nutritional hypervitaminosis A.

Fernández I, Darias M, Andree KB, Mazurais D, Zambonino-Infante JL, Gisbert E - BMC Dev. Biol. (2011)

Relative gene expression of RARA, RARB, RXRB and RBP(a), PPARA, PPARB and PPARG (b), Bmp2, TGFB1, IGF1 and IGF2 (c) and mgp, bglap, SPP1, SPARC and COL1A1 (d) in fishes fed with experimental diets (1.5×VA and 10×VA, 1.00*108 and 6.82*108 total VA IU kg-1 DW, respectively) at 18 and 60 dph. Relative gene expression measured as the fold change of the target gene with respect to the house-keeping gene (EF1α) at the appropriate sample time and compared with gene expression in the control group using REST 2008 software. Gene up- and down-regulations are highlighted in red and green (respectively), using different colour tone to identify each experimental group and sampled time. Only significantly higher or lower overall gene expression levels are represented (P < 0.05; n = 3 per dietary group).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3045981&req=5

Figure 8: Relative gene expression of RARA, RARB, RXRB and RBP(a), PPARA, PPARB and PPARG (b), Bmp2, TGFB1, IGF1 and IGF2 (c) and mgp, bglap, SPP1, SPARC and COL1A1 (d) in fishes fed with experimental diets (1.5×VA and 10×VA, 1.00*108 and 6.82*108 total VA IU kg-1 DW, respectively) at 18 and 60 dph. Relative gene expression measured as the fold change of the target gene with respect to the house-keeping gene (EF1α) at the appropriate sample time and compared with gene expression in the control group using REST 2008 software. Gene up- and down-regulations are highlighted in red and green (respectively), using different colour tone to identify each experimental group and sampled time. Only significantly higher or lower overall gene expression levels are represented (P < 0.05; n = 3 per dietary group).
Mentions: Regarding RA nuclear receptors, RARA presented at 18 dph a significant up-regulation (1.6 fold change respect to the control group) in 10×VA larvae with respect to control fishes (REST, P < 0.05; Figure 8a); however no significant up- or down-regulation of RARA was found at 60 dph regardless of the dietary conditions (REST, P > 0.05; Figure 8a). In contrast, while no differences in RARG mean gene expression ratio were found at 18 dph in larvae fed with increased dietary VA content (1.5×VA and 10×VA), a slight but significant RARG down-regulation (1.2 and 1.32 fold change, respectively) was found with respect to control larvae at 60 dph (REST, P < 0.05; Figure 8a). Interestingly, no change in gene expression was found concerning the gene RXRB at both sample times analyzed (REST, P > 0.05; Figure 8a).

Bottom Line: Present data reflects the specific gene expression patterns of several genes involved in larval fish RA signalling and skeletogenesis; and how specific gene disruption induced by a nutritional VA imbalance underlie the skeletal deformities.Our results are of basic interest for fish VA signalling and point out some of the potential molecular players involved in fish skeletogenesis.Increased incidences of skeletal deformities in gilthead sea bream fed with hypervitaminosis A were the likely ultimate consequence of specific gene expression disruption at critical development stages.

View Article: PubMed Central - HTML - PubMed

Affiliation: Unitat de Cultius Experimentals, IRTA Centre de Sant Carles de la Ràpita (IRTA-SCR), Crta, del Poble Nou s/n, 43540 - Sant Carles de la Ràpita (Spain) ignacio.fernandez@irta.es

ABSTRACT

Background: Vitamin A (VA) has a key role in vertebrate morphogenesis, determining body patterning and growth through the control of cell proliferation and differentiation processes. VA regulates primary molecular pathways of those processes by the binding of its active metabolite (retinoic acid) to two types of specific nuclear receptors: retinoic acid receptors (RARs) and retinoid X receptors (RXRs), which promote transcription of downstream target genes. This process is well known in most of higher vertebrates; however, scarce information is available regarding fishes. Therefore, in order to gain further knowledge of fish larval development and its disruption by nutritional VA imbalance, the relative expression of some RARs and RXRs, as well as several genes involved in morpho- and skeletogenesis such as peroxisome proliferator-activated receptors (PPARA, PPARB and PPARG); retinol-binding protein (RBP); insulin-like growth factors I and II (IGF1 and IGF2, respectively); bone morphogenetic protein 2 (Bmp2); transforming growth factor β-1 (TGFB1); and genes encoding different extracellular matrix (ECM) proteins such as matrix Gla protein (mgp), osteocalcin (bglap), osteopontin (SPP1), secreted protein acidic and rich in cysteine (SPARC) and type I collagen α1 chain (COL1A1) have been studied in gilthead sea bream.

Results: During gilthead sea bream larval development, specific expression profiles for each gene were tightly regulated during fish morphogenesis and correlated with specific morphogenetic events and tissue development. Dietary hypervitaminosis A during early larval development disrupted the normal gene expression profile for genes involved in RA signalling (RARA), VA homeostasis (RBP) and several genes encoding ECM proteins that are linked to skeletogenesis, such as bglap and mgp.

Conclusions: Present data reflects the specific gene expression patterns of several genes involved in larval fish RA signalling and skeletogenesis; and how specific gene disruption induced by a nutritional VA imbalance underlie the skeletal deformities. Our results are of basic interest for fish VA signalling and point out some of the potential molecular players involved in fish skeletogenesis. Increased incidences of skeletal deformities in gilthead sea bream fed with hypervitaminosis A were the likely ultimate consequence of specific gene expression disruption at critical development stages.

Show MeSH
Related in: MedlinePlus