microbiology, Vol 141, 713-719, Copyright © 1995 by Society for General Microbiology
Mini-chromosomes in Fusarium sporotrichioides are mosaics of dispersed repeats and unique sequences
R Nagy, E Taborhegyi, A Wittner and L Hornok
Agricultural Biotechnology Center, Hungary.
Variations in trichothecene patterns of 26 Fusarium sporotrichioides
isolates from different plant and geographic origins showed no correlation
with electrophoretic karyotype polymorphisms. When intact chromosomes were
examined, interisolate karyotype differences were observed only in the
mini-chromosome range. Further polymorphisms were revealed in Notl-digested
samples. By summing the Notl fragments the average genome size of F.
sporotrichioides was estimated to be 20.4 Mb. Mini-chromosomes shared
common sequences with the larger ones; however, clones (RMS-1 and RMS-2)
specific to these structures have also been found. These clones contained
no coding region and no promising similarities were observed when they were
compared to sequences held at GenBank. Mini-chromosomes in F.
sporotrichioides constitute a mosaic composed of dispersed repeats and
unique sequences. This mosaic structure was maintained in all
noninterbreeding, genetically isolated strains examined.
