A long terminal repeat retrotransposon Cgret from the phytopathogenic fungus Colletotrichum gloeosporioides on cranberry

A repetitive DNA element cloned from the cranberry fruit rot pathogen Colle totrichum gloeosporioides has been characterized. Sequence data indicate th at it is a long terminal repeat (LTR) retrotransposon of 7,916 base pairs. LTR of 544 base pairs occur at either end of an internal region of 6,828 ba se pairs. This element, designated Cgret (C. gloeosporioides retrotransposo n), encodes two putative polypeptides which have high homology to the gag a nd pol genes of other fungal retrotransposons. The sequence and structure s uggest that Cgret is a member of the gypsy group of LTR retrotransposons. T he Cgret retrotransposon was present in all of the cranberry isolates of th e fungus C. glaeosporioides from New Jersey and Massachusetts, but not in t he cranberry isolates from Wisconsin or Chile. Polymorphisms were detected among field isolates of C. gloeosporioides from various hosts, using hybrid ization probes derived from the LTR and the reverse transcriptase domain of Cgret. The structural integrity of Cgret suggests that it is still a funct ional retrotransposon and may be used as a molecular marker to study the ge netic diversity distribution of this fungal pathogen.