An EcoRI 1428 bp A + T-rich, DNA element (MYCDIRE: MYCorrhizal fungus Dispe
rsed Repetitive Element) has been identified in the genome of Scutellospora
castanea, an arbuscular mycorrhizal fungus. After sequencing, primers were
designed and used in PCR reactions to amplify portions of this element in
five species of arbuscular mycorrhizal fungi belonging to four genera of Gl
omales. Southern hybridizations and partial analysis of the main PCR produc
ts confirmed that this element was highly conserved in all the species. Sou
thern blot analysis of single and double digested DNA from two of the gloma
lean fungi gave smears suggesting that MYCDIRE is scattered throughout the
fungal genome. Sequence analyses revealed three copies of a previously repo
rted autonomously replicating sequence (ARS) from Saccharomyces cerevisiae
and comparisons indicated similarities of MYCDIRE with the autonomously rep
licating, A + T-rich element (ACARS) from Acremonium chrysogenum.