Removal of introns from transcribed RNA represents a crucial step during the production of
mRNA in eukaryotes. Available whole-genome sequences and expressed sequence tags (ESTs) have
increased our knowledge of this process and revealed various commonalities among eukaryotes. However,
certain aspects of intron structure and diversity are taxon-specific, which can complicate the accuracy of in
silico gene prediction methods. Using core genes, we evaluated the distribution and architecture of Fusarium
circinatum spliceosomal introns, and linked these characteristics to the accuracy of the predicted gene models
of the genome of this fungus. We also evaluated intron distribution and architecture in F. verticillioides,
F. oxysporum, and F. graminearum, and made comparisons with F. circinatum. Results indicated that
F. circinatum and the three other Fusarium species have canonical 59 and 39 splice sites, but with subtle
differences that are apparently not shared with those of other fungal genera. The polypyrimidine tract of
Fusarium introns was also found to be highly divergent among species and genes. Furthermore, the conserved
adenosine nucleoside required during the first step of splicing is contained within unique branch site motifs in
certain Fusarium introns. Data generated here show that introns of F. circinatum, as well as F. verticillioides,
F. oxysporum, and F. graminearum, are characterized by a number of unique features such as the CTHAH and
ACCAT motifs of the branch site. Incorporation of such information into genome annotation software will undoubtedly
improve the accuracy of gene prediction methods used for Fusarium species and related fungi.
Fourie, Gerda; Steenkamp, Emma Theodora; Ploetz, Randy C.; Gordon, Thomas R. (Tom); Viljoen, Adrienne(Elsevier, 2011-04)
Fusarium oxysporum is an asexual fungal species that includes human and animal pathogens and a
diverse range of nonpathogens. Pathogenic and nonpathogenic strains of this species can be
distinguished from each other with ...
De Vos, Lieschen; Van der Nest, Magrieta Aletta; Van der Merwe, Nicolaas Albertus (Albie); Wingfield, Michael J.; Wingfield, Brenda D.(Elsevier, 2011-09)
Fusarium circinatum and Fusarium subglutinans are two distinct species in the Gibberella
fujikuroi species complex. A genetic linkage map produced from an interspecific cross between
these species was used to identify ...