Interpretation of variability of mitochondrial genomes in the species Aspergillus carbonarius

For interpretation of intraspecific polymorphism and the considerable diffe rences in the size of mtDNAs among three groups of A. carbonarius, restrict ion maps were constructed from several enzymes. Functional maps were also d eveloped to compare genome organisations and gene content. The appearance o f various mtDNAs of A. carbonarius strains are different in size, but their gene content is almost identical. The 1.1 kb size difference between two c losely related subgroups (1a, 1b) can be attributed to the presence or abse nce of an intron in cox2 gene. This phenomenon demonstrates that the migrat ion of introns is possibly responsible for the development of variable mito chondrial genomes in nature. The striking differences in size and restricti on patterns between two main mtDNA groups might derive from both the intron al variations and the altered intergenic organisation.