Gypsy-class retrotransposon sequences in organisms related to the leaf mould fungus, Cladosporium fulvum.

Gypsy retrotransposons are a major branch of retroid elements and have been found in a wide diversity of eukaryotic organisms including CfT-1 in the tomato leaf mould pathogen, the fungus Cladosporium fulvum (syn. Fulvia fulva). We have examined organisms that are either ecologically or phylogenetically related to C. fulvum, for elements related to CfT-1. Using PCR and Southern hybridisation, similar sequences were found only in the co-genic fungus Cladosporium cladosporioides. This finding confirms the apparent ubiquity of retroelements, suggests that the phylogeny of retrotransposons is consistent with the phylogeny of their hosts and argues against frequent horizontal gene transfer.