XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:106-3

Investigação

106-3	Identification of transposable elements in genomes of Paracoccidioides species complex
Authors:	Patricia Cisalpino (UFMG - Universiade Federal de Minas Gerais)

Abstract

The genetic polymorphism of Paracoccidioides has been widely demonstrated by different authors using several molecular techniques. The effects of transposable elements (TEs) may be responsible for the genetic polymorphism observed in fungal genomes. Studies based on gene genealogies suggested that the genus consists of at least four phylogenetic species, S1 (P. brasiliensis), PS2, PS3, and a quite distinct lineage referred to as Pb01-like, now proposed to be a new species, P. lutzii. Recently, three isolates corresponding to distinct Paracoccidioides phylogenetic lineages had their genomes sequenced. Our group carried out a genomic survey for the identification and characterization of class II transposable elements (DNA transposons) in their genomic sequence assemblies. Eight new Tc1/mariner families, referred to as Trem (Transposable element mariner), labeled A - H were identified. Elements from each family have 65-80% sequence similarity with other Tc1/mariner elements. They are flanked by 2-bp TA target site duplications and different termini. Encoded DDD-transposases, some of which have complete ORFs, indicated that they could be functionally active. The distribution of Trem elements varied between the genomic sequences characterized as belonging to P. brasiliensis (S1 and PS2) and P. lutzii. TremC and H elements would have been present in a hypothetical ancestor common to P. brasiliensis and P. lutzii, while TremA, B and F elements were either acquired by P. brasiliensis or lost by P. lutzii after speciation. Although TremD and TremE share about 70% similarity, they are specific to P. brasiliensis and P. lutzii, respectively. This suggests that these elements could either have been present in a hypothetical common ancestor and have evolved divergently after the split between P. brasiliensis and P. lutzii, or have been independently acquired by horizontal transfer. Families were distinguished based on significant BLAST identities between transposases and/or TIRs. The expansion of Trem in a putative ancestor common to the species P. brasiliensis and P. lutzii would have given origin to TremC and TremH, while other elements could have been acquired or lost after speciation had occurred. The results may contribute to our understanding of the organization and architecture of genomes in the genus Paracoccidioides.

Keyword: DNA tranposons, Paracoccidioides, class II transposons

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