Table 1. Distribution of introns in Cyt b genes of eukaryotic organisms.

Taxondivision1	No. ofCyt b genes2		Frequency of species with introns in the Cyt b gene (%)
	All	withintron	Unknown3		1 intron		2 introns		3 introns		4 introns		5 introns		6 introns		7 introns		Total
			Spp.	%	Spp.	%	Spp.	%	Spp.	%	Spp.	%	Spp.	%	Spp.	%	Spp.	%	Spp.	%
Fungi	465	69	11	2.37	19	4.09	14	3.01	10	2.15	3	0.86	4	0.65	4	0.86	4	0.86	69	14.84
Metazoa	2062	3	0		3	0.15	0		0		0		0		0		0		3	0.15
Plants	440	9	0		2	0.45	3	0.68	4	0.91	0		0		0		0		9	2.05
Protista	309	11	1	0.32	6	1.94	2	0.65	1	0.32	1		0	0.32	0		0		11	3.56
Total	3276	92	12	0.37	30	0.92	19	0.58	15	0.46	4	0.12	4	0.12	4	0.12	4	0.12	92	2.81

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.