Title:	Caracterização in Silico de biossensores em Colossoma Macropomum: diagnóstico molecular e monitoramento de ambientes impactados
Authors:	Casanova , Frida Mesel
metadata.dc.contributor.advisor:	Nozawa , Sérgio Ricardo
Keywords:	Colossoma macropomum Peixes Expressão gênica Metais pesados Biblioteca de cDNA
Issue Date:	16-Oct-2008
Publisher:	Instituto Nacional de Pesquisa da Amazônia - INPA
metadata.dc.publisher.program:	Genética, Conservação e Biologia Evolutiva - GCBEv
metadata.dc.description.resumo:	The large diversity of fish found in the Amazon Basin represents over half the total aquatic vertebrate species known in the world. Colossoma macropomum (tambaqui) is frequently used as a model species in the study of physiological processes modulated by environmental variables in the Amazon. Metals in aquatic environments, such as copper and cadmium, may interfere with the biological processes of fish severely due to their large branchial area exposed to the environment. Juvenile tambaquis were exposed to three different treatments: (1) 1- and 3-h exposure to subletal concentrations of copper [CuSO4.5H2O (20 μg/L)], (2) 1- and 3-h exposure to subletal concentrations of cadmium [Cd(NO3).4H2O (10 μg/L), (3) mechanical stress for 5 min daily during 3 consecutive days. The liver (treatments 1 and 2) and muscle (treatment 2) of treated fish were removed for cDNA library construction and sequencing analysis. The data obtained were categorized through BLAST2GO, the Danio rerio (zebrafish) and Ictalurus punctatus (bagre de canal) databases available from NCBI (National Center for Biotechnology Information, USA, www.ncbi.nlm.nih.gov) and compared to the cDNA library of tambaqui exposed to the same treatments. Simultaneously, gene expression of enzyme catalase, heat shock protein, glutamine synthase, and cytochrome p450 obtained from the I. punctatus and D. rerio, from ESTs. Databases were analyzed by RT-PCR. Genes rag 2 and trop were selected from the tambaqui library and submitted to qPCR. The enzymatic activities of GST and catalase in fish treated with heavy metals were determined. No significant difference was found, possibly due to the short exposure time and the expression of their respective mRNAs. The Ictalurus punctatus database provided a larger amount of grouped genes (37%) in biological processes, similarly to the Danio rerio (40%) database. The analysis of the libraries of tambaqui revealed the expression of approximately 900 genes, including GST, catalase, CYP450, and HIF-2. The number of transcripts of genes rag 2 and tropomyosin in the qPCR reaction stood out for the increased levels of mRNA after the exposure of fish to cadmium ion for 3 h, while the muscle of fish submitted to mechanical stress did not present changes in the expression of transcripts in relation to the control.
Appears in Collections:	Mestrado - GCBEv

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