title: Genomic characterization, phylogeny and gene regulation of g-type lysozyme in sole (Solea senegalensis).
abstract: The g-type lysozyme is a key protein of the innate immune system to fight bacterial infections. In this study we cloned and characterized the gene encoding for g-type lysozyme in Senegalese sole (Solea senegalensis). The deduced amino acid sequence comprised 195 residues containing the three conserved catalytic residues and two cysteines. A BAC analysis revealed that the gene is structured in 5 exons and 4 introns. Also, two polyadenylation signals that generate two cDNAs differing in 3'-UTR length were detected. Promoter analysis showed the presence of the main cis-acting elements involved in the transcriptional regulation of the gene. At genomic level, the g-type lysozyme was associated with mucolipin 1 and the peptidoglycan recognition protein 2 conforming a cluster of antidefensive genes with a well-conserved synteny across Percomorpha. FISH analysis using the BAC clone revealed a single hybridization signal located in an acrocentric chromosome pair. The phylogenetic analysis confirmed that the g-type lysozyme represents a complex group in fish that has been shaped by gene duplications and diversification with several positions under Darwinian selection. Expression analysis in juvenile tissues indicated that transcript levels were higher in gills, spleen and heart. During development, gene expression activated just at the beginning of metamorphosis, increasing progressively until climax. Hormonal treatments demonstrated that this gene was regulated positively by thyroid hormones during development and negatively by dexamethasone. In contrast, no response was observed after all-trans retinoic acid or 4-diethylaminobenzaldehyde treatments. Finally, treatments using lipopolysaccharide, lipoteichoic acid, peptidoglycan, zymosan and poly(I:C) activated gene expression in a time- and tissue-specific manner. Taken together, data indicate that g-type lysozyme is a high evolutionary conserved gene that diversified to adapt to changing environment and pathogen conditions. Gene expression can be activated by diverse pathogen stimuli and modulated by physiological factors with important consequences for the aquaculture of this species.
authors: IFAPA centro El Toruño, Junta de Andalucía, Camino Tiro de pichón s/n, 11500 El Puerto de Santa María, Cádiz, Spain.
authors: Marian
authors: M
authors: Ponce
authors: Emilio
authors: E
authors: Salas-Leiton
authors: Ana
authors: A
authors: Garcia-Cegarra
authors: Anais
authors: A
authors: Boglino
authors: Olivier
authors: O
authors: Coste
authors: Carlos
authors: C
authors: Infante
authors: Enric
authors: E
authors: Gisbert
authors: Laureana
authors: L
authors: Rebordinos
authors: Manuel
authors: M
authors: Manchado
mesh_terms: D000367:Age Factors; D000595:Amino Acid Sequence; D000818:Animals; D017756:Aquaculture; D001483:Base Sequence; D022202:Chromosomes, Artificial, Bacterial; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D003907:Dexamethasone / Q000494:pharmacology; D019143:Evolution, Molecular; D005412:Flatfishes / Q000235:genetics*; D040461:Gene Components; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology*; D017404:In Situ Hybridization, Fluorescence; D008070:Lipopolysaccharides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009113:Muramidase / Q000235:genetics*; D010457:Peptidoglycan / Q000494:pharmacology; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics; D017422:Sequence Analysis, DNA; D013682:Teichoic Acids / Q000494:pharmacology; D013963:Thyroid Hormones / Q000494:pharmacology; D015054:Zymosan / Q000494:pharmacology
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D008070:Lipopolysaccharides; D010457:Peptidoglycan; D013682:Teichoic Acids; D013963:Thyroid Hormones; C009900:lipoteichoic acid; D003907:Dexamethasone; D015054:Zymosan; D009113:Muramidase