Biased Distribution of Inverted and Direct Alus in the Human Genome: Implications for Insertion, Exclusion, and Genome Stability

Table 2.

Truncation of “Heads” in Alu Pairs According to Orientation and Distance

Orientation of pairs		Separation distance (b + c) (bp)		Frequency
Orientation of pairs		Separation distance (b + c) (bp)		internal truncation %	external truncation %	no truncation %	total no.
Direct Repeats
CC	0–20	39.8	4.2	55.9	10170
	21–40	36.3	17.8	45.9	3541
	41–60	34.4	26.8	38.8	2242
	61–80	27.0	31.5	41.5	1962
	81–100	24.4	39.2	36.3	1923
	101–120	24.8	35.3	40.0	1655
Inverted Repeats
CD	0–20	50.0	N/A	50.0	66
	21–40	13.8	N/A	86.2	747
	41–60	28.4	N/A	71.6	524
	61–80	36.2	N/A	63.8	525
	81–100	38.3	N/A	61.7	468
	101–120	50.8	N/A	49.2	496

DC	0–20	N/A	56.4	43.6	280
	21–40	N/A	48.9	51.1	485
	41–60	N/A	47.4	52.6	490
	61–80	N/A	46.4	53.6	455
	81–100	N/A	45.2	54.8	423
	101–120	N/A	48.6	51.4	449

↵Truncations are ≥5 bp
↵Includes truncation ≤5 bp

This Article

Genome Res. 2001. 11: 12-27

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