Richard Reinhardt

Publications (3)4.98 Total impact

• Article: Characteristics of fads2 gene expression and putative promoter in European sea bass (Dicentrarchus labrax): comparison with salmonid species and analysis of CpG methylation.

  Florian Geay, José Zambonino-Infante, Richard Reinhardt, Heiner Kuhl, Ester Santigosa, Chantal Cahu, David Mazurais
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  ABSTRACT: Marine fish species exhibit low capacity to biosynthesise highly unsaturated fatty acid (HUFA) in comparison to strict freshwater and anadromous species. It is admitted that the Delta(6) desaturase (FADS2) is a key enzyme in the HUFA biosynthetic pathway. We investigated by quantitative PCR the relative amounts of FADS2 mRNA in European sea bass (Dicentrarchus labrax) in comparison with a salmonid species, the rainbow trout (Oncorhynchus mykiss L.). The analysis of the expression data was performed regarding the difference of the characteristics of a critical fragment of the fads2 gene promoter between sea bass and Atlantic salmon. The lower level of fads2 gene expression observed in sea bass suggested that fads2 gene putative promoter, which exhibited an E-box like Sterol Regulatory Element (SRE) site but lacked a Sp1 site, is less active in this marine species. The cytosine methylation of CpG sites in the putative promoter region including E-box like SRE and NF-Y binding sites of sea bass fads2 gene was also investigated following a nutritional conditioning of larvae. However, no significant difference of CpG methylation could be found for any of the 28 CpGs analysed between larvae fed diet with high or low HUFA contents. In conclusion, the present data revealed lower constitutive expression of the fads2 gene possibly related to different characteristics of gene promoter in sea bass in comparison with salmonid species, and indicated that long-term conditioning of fads2 gene expression did not influence the methylation of the gene promoter at potential SRE binding site.
  Marine Genomics 03/2012; 5:7-13. · 1.55 Impact Factor
• Source

  Available from: Laurent Corcos

  Article: Cloning, tissue expression analysis, and functional characterization of two Δ6-desaturase variants of sea bass (Dicentrarchus labrax L.).

  Ester Santigosa, Florian Geay, Thierry Tonon, Herve Le Delliou, Heiner Kuhl, Richard Reinhardt, Laurent Corcos, Chantal Cahu, José Luis Zambonino-Infante, David Mazurais
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  ABSTRACT: Fish are the main source of the n-3 highly unsaturated fatty acids, which are crucial for human health. Their synthesis from C(18) precursors is mediated by desaturases and elongases, but the activity of these enzymes has not been conclusively established in marine fish species. This study reports the cloning, tissue expression, and functional characterization of a sea bass (Dicentrarchus labrax L.) Δ6-desaturase and one of its splicing variants. Two cDNAs with open reading frames of 1,346 and 1,354 bp were cloned and named D6D and D6D-V, respectively. Both deduced protein sequences (445 and 387 amino acids, respectively) contained two transmembrane regions and the N-terminal cytochrome b(5) domain with the HPGG motif characteristic of microsomal desaturases. D6D presents three histidine-rich regions, whereas in D6D-V, an insertion of eight nucleotides in the boundaries of exons 10 and 11 modified the third histidine-rich domain and led to insertion of a premature STOP codon, resulting in a shorter predicted protein. Quantitative real-time polymerase chain reaction assay of gene expression showed that D6D was highly expressed in the brain and intestine, and to a lesser extent, in muscle and liver; meanwhile, D6D-V was expressed in all tissues tested, but at level at least 200-fold lower than D6D. Functional analysis in yeast showed that sea bass D6D encodes a fully functional Δ6-desaturase with no residual Δ5-desaturase activity. This desaturase does not exhibit a clear preference for n-3 versus n-6 C(18) substrates. Interestingly, D6D-V is a nonfunctional protein, suggesting that the C-terminal end is indispensable for protein activity.
  Marine Biotechnology 03/2010; 13(1):22-31. · 3.43 Impact Factor
• Article: Cloning, Tissue Expression Analysis, and Functional Characterization of Two Δ6-Desaturase Variants of Sea Bass (Dicentrarchus labrax L.)

  Ester Santigosa, Florian Geay, Thierry Tonon, Herve Le Delliou, Heiner Kuhl, Richard Reinhardt, Laurent Corcos, Chantal Cahu, José Luis Zambonino-Infante, David Mazurais
  [show abstract] [hide abstract]
  ABSTRACT: Fish are the main source of the n-3 highly unsaturated fatty acids, which are crucial for human health. Their synthesis from C18 precursors is mediated by desaturases and elongases, but the activity of these enzymes has not been conclusively established in marine fish species. This study reports the cloning, tissue expression, and functional characterization of a sea bass (Dicentrarchus labrax L.)
  Marine Biotechnology. 13(1):22-31.