The Roles and Evolutionary Patterns of Intronless Genes in Deuterostomes

Table 1

The C-values and statistics for genes (intron and intronless) in each species.

Species	Sea-Urchin	Sea-Squirt	Zebrafish	Chicken	Platypus	Human
C-value (pg)	0.89	0.20	1.75	1.25	3.06	3.5
N	—	19858	40585	22194	26836	88237
I	2482 (8.6)	1448 (11.2)	2169 (8.6)	1659 (10.2)	930 (7.9)	6229 (16.7)
NR*	676	1263	856	1029	516	2290
NRI*	8792	8502	10620	9502	7840	12823
R **	621 (92)	110 (9)	274 (32)	156 (15)	86 (17)	1321 (58)
C **	212 (31)	191 (15)	269 (31)	186 (18)	133 (26)	665 (29)

C: values are obtained from http://www.genomesize.com/.
N: number of proteins encoded by intron and intronless genes, obtained from Ensemble (http://www.ensembl.org/index.html).
I: number of intronless genes in each genome, numbers in parentheses are percentages of intronless genes account for total genes.
NR: number of nonredundant intronless gene clusters.
NRI: number of nonredundant intron gene clusters.
R: number of nonredundant clusters that represent more than one intronless gene.
C: number of clusters that represent both a nonredundant intronless and a nonredundant intron-containing gene.
*Clustered using CD-Hit (identity = 0.3).
**Numbers in parentheses are percentages they account for all nonredundant intronless gene clusters.