Table 2. Phase of U2- and U12-dependent introns.

	U2-dependent introns		U12-dependent introns
	Number	Percentage	Number	Percentage
Phase 0	5263	47.4	59	20.8
Phase 1	3372	30.3	118	41.5
Phase 2	2482	22.3	107	37.7
Total	11 117	100	284	100

The number and percentage of U2- and U12-dependent introns that fall into the three possible phase classes are shown. Introns are phase 0 when the intron occurs between codons, phase 1 when the intron is found 1 base into the codon and phase 2 when the intron is found 2 bases into the codon. U2-dependent intron data is from Long et al (23).