Markup | Genome Research

Table 2.

Observed and Expected Numbers of Symmetrical Nonboundary Exons or Sets of Nonboundary Exons[i]

No. of exons	Comb.[ii]	Obs.[iii]	Exp.[iv]	P
1 exon (2007)	0–0	508	533	0.21
	1–1	154	139.7	0.21
	2–2	96	97.6	0.87
	$\sum$	758	770.3	0.57
2 exons (842)	0–0	243	252.9	0.46
	1–1	59	55.2	0.6
	2–2	27	32.3	0.34
	$\sum$	329	340.4	0.42
3 exons (454)	0–0	121	130	0.35
	1–1	30	32.2	0.69
	2–2	16	17.1	0.79
	$\sum$	167	179.3	0.24
4 exons (301)	0–0	95	92.4	0.75
	1–1	26	20.5	0.21
	2–2	5	10	0.11
	$\sum$	126	122.9	0.72
5 exons (187)	0–0	52	53.9	0.76
	1–1	22	17	0.2
	2–2	4	4.8	n.d.
	$\sum$	78	75.7	0.73
6 exons (118)	0–0	37	36.8	0.97
	1–1	14	11.6	0.46
	2–2	1	1.9	n.d.
	$\sum$	52	50.3	0.75

[i] The total number of cases in each group are indicated in parentheses. The expected values were calculated based on the phase frequencies of flanking introns (see Methods). Summed symmetrical combinations are shown in boldface. Some P-values were not determined (n.d.) due to the low sample size.

[ii] Combination of flanking intron phases.

[iii] Observed.

[iv] Expected.