title: Divergence of a linear and a circular plasmid in disjunct natural isolates of the fungus Neurospora.
abstract: It is known from DNA hybridization and other studies that Neurospora plasmids are widely distributed across species of this genus. However few comparisons have been performed of the structure of apparently identical plasmids in widely differing geographical and biological locations. We compare pairs of circular and linear mitochondrial plasmids from distant geographical locations. The circular plasmids (LaBelle and Harbin-1) were from different ecotypes of N. intermedia and the linear plasmids (maranhar and Harbin-3) were from different species (N. crassa and N. intermedia). The structures are highly similar at the sequence level showing that they are closely related. Most of the differences are outside the presumptive genes (coding for polymerases). Furthermore, most of the proposed functional motifs have been retained. Sequence divergence is compatible with a distribution model by vertical descent from a common ancestor, but horizontal transmission cannot be ruled out.
authors.affiliation: Department of Botany, University of British Columbia, 6270 University Boulevard, Vancouver, British Columbia, V6T 1Z4, Canada.
authors.forename: Y
authors.initials: Y
authors.lastname: Xu
authors.forename: S
authors.initials: S
authors.lastname: Yang
authors.forename: I
authors.initials: I
authors.lastname: Turitsa
authors.forename: A
authors.initials: A
authors.lastname: Griffiths
mesh_terms: D000595:Amino Acid Sequence; D004271:DNA, Fungal; D008969:Molecular Sequence Data; D009491:Neurospora / Q000235:genetics*; D009492:Neurospora crassa / Q000235:genetics*; D010957:Plasmids
chemical_list: D004271:DNA, Fungal