Distribution of introns in Cyt b genes of eukaryotic organisms.

1In the GOBASE database, taxon divisions Fungi, Metazoa were equal to kingdoms Fungi, Animalia, respectively. Plant division represented the Plantae kingdom except for a few lower plants (i.e. some green algae). Protista included kingdoms Chromista and Protozoa, and some lower plants (green algae) which should have been in the kingdom Plantae based on the Cavalier-Smith’s classification system [5].2Data were obtained by gene search and intron search options with Cyt b gene (cob) as gene name in GOBASE database [41], and some of our own sequences were added, i.e. seven Cyt b introns from M. fructicola, M. fructigena, M. laxa and M. yunnanensis, six Cyt b introns from M. mumecola and U. virens.3The precise intron numbers were not known because these Cyt b genes were partial sequences. Spp. indicates biological species.