Phylogenetic analyses suggest reverse splicing spread of group I introns in fungal ribosomal DNA.

ABSTRACT:

Background

Group I introns have spread into over 90 different sites in nuclear ribosomal DNA (rDNA) with greater than 1700 introns reported in these genes. These ribozymes generally spread through endonuclease-mediated intron homing. Another putative pathway is reverse splicing whereby a free group I intron inserts into a homologous or heterologous RNA through complementary base-pairing between the intron and exon RNA. Reverse-transcription of the RNA followed by general recombination results in intron spread. Here we used phylogenetics to test for reverse splicing spread in a taxonomically broadly sampled data set of fungal group I introns including 9 putatively ancient group I introns in the rDNA of the yeast-like symbiont Symbiotaphrina buchneri.

Results

Our analyses reve

SUBMITTER: Bhattacharya D 

PROVIDER: S-EPMC1299323 | biostudies-literature | 2005 Nov

REPOSITORIES: biostudies-literature