XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:129-1

Poster (Painel)

129-1	IN SILICO IDENTIFICATION AND MOLECULAR CARACTERIZATION OF TWO COPIA-LIKE RETROTRANSPOSONS (PaSret AND MaSret)IN THE GENOME OF THE PATHOGENIC FUNGUS Paracoccidioides brasiliensis
Authors:	Marco Aurelio Soares (UFMG - Universidade Federal de Minas GeraisFIOCRUZ - Fiocruz-Centro de Pesquisa Renê Rachou) ; Jeronimo Conceicao Ruiz (FIOCRUZ - Fiocruz-Centro de Pesquisa Renê Rachou) ; Patricia Silva Cisalpino (UFMG - Universidade Federal de Minas Gerais)

Abstract

Transposable elements are seen as key agents in the development and restructuring of genomes, acting through different mechanisms such as transposition, ectopic recombination, horizontal transfer and epigenetic inactivation. There are few reports on the presence or characterization of repetitive elements in the P. brasiliensis genome. In this study, integrated approaches of bioinformatics and molecular biology were used to identify, map and characterize the repertoire of transposable elements in the fungus sequenced genomes (isolates Pb01, Pb03 and Pb18). The methodology employed involved: a) clustering of data available in databases in the public domain regarding the ESTs (Expressed Sequence Tags) of the fungus. During the study, three test scripts PERL (Practical Extraction and Report Language) were developed; b) the structural and functional annotation of 12,922 generated contigs; c) the computational graphical mapping of the retrotransposable elements identified in the sequenced genomes of isolates Pb01, Pb03 and Pb18(Broad Institute); d) identification of two distinct new copia-like retrotransposons named PaSret and MaSret; e) a PCR-based method for the amplification, cloning and sequencing of the genomic region coding for the reverse transcriptases of each element. Both elements (PaSret and MaSret) are under molecular characterization. The element PaSret has 5183pb in length and it is flanked by 103bp LTRs (long terminal repeats). This element was amplified, cloned and partially sequenced confirming the identity of the reverse transcriptase-containing fragment. The element MaSret has 5686pb in length being flanked by 98bp LTR. Multiple copies of both elements were identified in the genomes of Pb01, Pb03 and Pb18 isolates. Physical mapping is also being executed by Southern blot hybridization using sequenced amplicoms as probes. Although many truncated copies have been found by computational analysis, only a few full length copies containing reverse transcriptase and integrase domains were observed. The computational methodology developed as well as the annotation and characterization of the elements will be presented, focusing on the fact that these are the first Copia-like elements described in the genome of this pathogenic fungus.਀匀甀瀀瀀漀爀琀攀搀戀礀䌀一倀焀

Keyword: Copia-like retrotransposon, Paracoccidioides brasiliensis, Pathogenic fungus

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