Divergent histories of rDNA group I introns in the lichen family physciaceae

Dawn Simon, Jessica Moline, Gert Helms, Thomas Friedl, Debashish Bhattacharya

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

The wide but sporadic distribution of group I introns in protists, plants, and fungi, as well as in eubacteria, likely resulted from extensive lateral transfer followed by differential loss. The extent of horizontal transfer of group I introns can potentially be determined by examining closely related species or genera. We used a phylogenetic approach with a large data set (including 62 novel large subunit [LSU] rRNA group I introns) to study intron movement within the monophyletic lichen family Physciaceae. Our results show five cases of horizontal transfer into homologous sites between species but do not support transposition into ectopic sites. This is in contrast to previous work with Physciaceae small subunit (SSU) rDNA group I introns where strong support was found for multiple ectopic transpositions. This difference in the apparent number of ectopic intron movements between SSU and LSU rDNA genes may in part be explained by a larger number of positions in the SSU rRNA, which can support the insertion and/or retention of group I introns. In contrast, we suggest that the LSU rRNA may have fewer acceptable positions and therefore intron spread is limited in this gene.

Original languageEnglish (US)
Pages (from-to)434-446
Number of pages13
JournalJournal of Molecular Evolution
Volume60
Issue number4
DOIs
StatePublished - Apr 1 2005

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Keywords

  • Large subunit rRNA
  • Lichens
  • Physciaceae
  • Small subunit rRNA
  • rRNA group I introns

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Molecular Biology
  • Genetics

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