Título:	Identificação de genes potencialmente envolvidos na formação do edema labial na espécie Colossoma macropomum (Cuvier, 1818) (Characiformes : Serrasalmidae)
Autor:	Fagundes, Daniel Barros
Orientador:	Val, Adalberto Luis
Palavras-chave:	Colossoma macropomum Expressão gênica Hipóxia aquática Tambaqui
Data do documento:	6-Jun-2012
Editor:	Instituto Nacional de Pesquisa da Amazônia - INPA
Programa:	Genética, Conservação e Biologia Evolutiva - GCBEv
Resumo:	The periodic oscillation in the level of the Amazonian rivers confers dynamicity to physiographic and limnological characteristics of the Basin. Often, these oscillations lead to large variations in the concentrations of dissolved oxygen in the water that can be observed over a single day, requiring to the ichthyofauna continuous adjustments of behavioral, biochemical, physiological and morphological traits. To understand the mechanisms behind the lip expansion, a common morphological and anatomical adaptation to certain fish species belonging to the Characiformes order, it was proposed a serial analysis of gene expression (SAGE) on the SOLiD™ Platform. For this, individuals of Colossoma macropomum were exposed to acute hypoxia (0.3 mgO2/L), keeping a control group under normal conditions of oxygen (0.7 mgO2/L). Following, the general procedures were: (I) extracting RNA from lip tissue, (II) preparing pools of RNA samples, (III) constructing SOLiD™ SAGE™ libraries, (IV) in vitro clonal amplifying libraries by ePCR, (V) enriching amplified sequences, (VI) sequencing, (VII) bioinformatics analyzes and (VIII) gene categorization. Out of 115 million tags sequenced, 2.24 million were unique tags. After alignment of unique tags with the reference sequences of the species Danio rerio it was possible to identify 24014 genes, 51.24% (Log2FC ≤ -0,1) repressed and 42.77% (Log2FC ≥ 0,1) activated during under hypoxia. From these results we selected 10 genes (HIF1A, ARNT, HIF1AN, VHL, VEGFC, VEGFR2, PLCG1, TRPC6, NOS1 and GUCY1A3) that participate directly or indirectly in the process of increased microvascular permeability, favoring the lip expansion of the C. macropomum when exposed to low oxygen tensions. We propose that the pathway for the expression of this phenotype began with stabilizing protein HIF1A and formation of the heterodimer HIF1 after dimerization with ARNT protein. HIF1 then binds in the promoter region of the gene VEGFC stimulating your transcription. Once translated, the VEGFC is recognized by VEGFR2 receptor inducing the synthesis of DAG through PLCG1 protein. The DAG promotes the opening of cationic channels of TRPC6 cell membrane, facilitating the influx of calcium ions from extracellular to intracellular medium. This increase in intracellular calcium concentration which activates the enzyme NOS1 passes to synthesize NO. This activates the GUCY1A3 enzyme that converts GTP to cGMP, favoring increased levels of cGMP which induce the formation of transvascular pathways that facilitate plasma leaking into the interstitial region, thus causing swelling of the lower lip.
Aparece nas coleções:	Mestrado - GCBEv

Este item está licenciada sob uma Licença Creative Commons