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Identification and gene expression of the enzymes arginase 1, arginase 2, and pro-inflammatory cytokines in Pseudoplatystoma corruscans and Pseudoplatystoma reticulatum, immunized with Ichthyophthirius multifiliis.

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Gabriel Sassarão Alves Moreira
Total Authors: 1
Document type: Doctoral Thesis
Press: Pirassununga.
Institution: Universidade de São Paulo (USP). Faculdade de Zootecnica e Engenharia de Alimentos (FZE/BT)
Defense date:
Examining board members:
Antonio Augusto Mendes Maia; Hélio José Montassier; Paulo Sérgio Monzani; Fabiana Pilarski; Ricardo Luiz Moro de Sousa
Advisor: Antonio Augusto Mendes Maia

The ciliate protozoan Ichthyophthirius multifiliis has been reported in various freshwater fishes and stands out as an important pathogen for being responsible to severe losses to both food and aquarium fish production. Among the fish species explored economically in Brazil it can be highlight the pintado (Pseudoplatystoma corruscans (Spix & Agassiz, 1829) and cachara (Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889). At this study the parasite I. multifiliis was original isolated from a petshop infected fish and maintained by serial transmission on naive pintado (P. corruscans) to obtain the infecting form (teronte) used at immunizations. The molecular identification of fish was realized through the amplification and sequencing of RAG2 gene, were the pintado (P. corruscans) and cachara (P. reticulatum) were homozygous, while the hybrid between those fish was considered heterozygous for this gene. At the partial gene characterization from fishes belonging to the Pseudoplatystoma family, the PCR amplification result in sequences of 530, 815, 400, 280 and 300 pb of the genes arginase 1, arginase 2, IL1-β, IL-8 e TNFα respectively, which were used to construct of specific primers for the quantitative real-time PCR (qPCR). The gene expression at P. corruscans and P. reticulatum immunized with live theronts of I. multifiliis was evaluated 6, 12, 18 and 24 hours after the immunization, where it was collected samples of the spleen, liver and heady kideny. The gene expression of the organs of pintado (P. corruscans) showed similar pattern of expression. An up-regulation with statistical significance was observed for: arginase 2 at 6 and 18 hours at spleen, 6 h at kidney and 6, 18 and 24 h at head kidney; the gene of IL1-β at 24 h at spleen, 18 and 24 hours at head kidney; the gene of IL-8 at 18 h at spleen. The genes of arginase 1 and TNFα didn\'t showed statistical significant regulation at this experiment. At the gene expression of cachara (P. reticulatum) only the spleen had a statistical alteration after theronts immunization where the arginase 2, IL-8 and TNFα was up-regulated at 6 h and 18 h, while the arginase 1 and IL1-β didn\'t showed statistical alteration. (AU)

FAPESP's process: 13/16738-9 - Expression of genes in Pseudoplatystoma corruscans, Pseudoplatystoma reticulatum,and its hybrid immunized with Ichthyophthirius multifiliis
Grantee:Gabriel Sassarão Alves Moreira
Support type: Scholarships in Brazil - Doctorate