Evidence of ectopic recombination and a repeat-induced point (RIP) mutation in the genome of Sclerotinia sclerotiorum, the agent responsible for white mold.

Mateus Ferreira Santana,Míriam Goldfarb,Marisa Vieira De Queiroz,Tânia Maria Fernandes Salomão,Everaldo Gonçalves De Barros

doi:10.1590/1678-4685-gmb-2015-0241

Mateus Ferreira Santana, Míriam Goldfarb + Show 3 more

Open Access

https://doi.org/10.1590/1678-4685-gmb-2015-0241

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Abstract

Two retrotransposons from the superfamilies Copia and Gypsy named as Copia-LTR_SS and Gypsy-LTR_SS, respectively, were identified in the genomic bank of Sclerotinia sclerotiorum. These transposable elements (TEs) contained direct and preserved long terminal repeats (LTR). Domains related to codified regions for gag protein, integrase, reverse transcriptase and RNAse H were identified in Copia-LTR_SS, whereas in Gypsy-LTR_SS only domains for gag, reverse transcriptase and RNAse H were found. The abundance of identified LTR-Solo suggested possible genetic recombination events in the S. sclerotiorum genome. Furthermore, alignment of the sequences for LTR elements from each superfamily suggested the presence of a RIP (repeat-induced point mutation) silencing mechanism that may directly affect the evolution of this species.

Highlights

Transposable elements (TEs) are ubiquitous DNA sequences in the genome that have the ability to move from one place to another (Kidwell, 2005)
All class I TEs are transposed by intermediate RNA which is transcribed from a copy of the genome and the cDNA is obtained from a reverse transcriptase codified by the element itself
These proteins include a protease involved in protein maturation and cleavage, a reverse transcriptase that reverse-transcribes the RNA into cDNA, an integrase that allows transposon insertion into the genome, and an RNAse H that degrades the RNA regions during cDNA synthesis

Summary

Introduction

Transposable elements (TEs) are ubiquitous DNA sequences in the genome that have the ability to move from one place to another (Kidwell, 2005). All class I TEs are transposed by intermediate RNA which is transcribed from a copy of the genome and the cDNA is obtained from a reverse transcriptase codified by the element itself. The LTR gag and pol regions are structural compounds of the Copia and Gypsy retrotransposons.

Results

Conclusion