Transposition of MINE, a composite retrotransposon, in the avirulence gene ACE1 of the rice blast fungus Magnaporthe grisea

Fungal Genet Biol. 2005 Sep;42(9):761-72. doi: 10.1016/j.fgb.2005.05.001.

Abstract

The ACE1 avirulence gene allele from the rice blast fungus Magnaporthe grisea was characterized in virulent isolate 2/0/3, revealing the insertion of a 1.9 kb MINE retrotransposon in the last ACE1 exon. MINE is a novel chimeric element composed of a transcribed non-coding sequence of 1.1 kb (WEIRD) fused to a 5'-truncated MGL retrotransposon. MINEs were found in high copy number in M. grisea isolates from rice (68 copies) and as a single copy in isolate CD156 from Eleusine. MINEs vary in size (1.3-6.7 kb) with conserved 5' WEIRD sequences and variable 3' MGL sequences. MGLs fused to WEIRDs correspond to different 5'-truncated MGLs with conserved 3' ends. The organization and diversity of MINEs suggest that these retrotransposons result from independent fusions between WEIRD and 5'-truncated MGLs. Such chimera could be formed during MGL reverse transcription as proposed for human U6-LINE1 chimeric retrotransposons and integrated into M. grisea genome using MGL machinery.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • DNA, Fungal / chemistry
  • DNA, Fungal / genetics
  • Eleusine / microbiology
  • Exons / genetics
  • Gene Dosage
  • Genes, Fungal*
  • Magnaporthe / genetics*
  • Magnaporthe / pathogenicity
  • Molecular Sequence Data
  • Oryza / microbiology
  • Retroelements / genetics*
  • Sequence Analysis, DNA
  • Virulence / genetics*

Substances

  • DNA, Fungal
  • Retroelements

Associated data

  • GENBANK/AJ851230
  • GENBANK/AJ851231
  • GENBANK/AJ851232