Table 3.

Deletions observed in CRISPR locus 2 of S. islandicus REY15A and locus A of S. solfataricus P2.

		Deletions in S. islandicus CRISPR locus 2		Deletions or insertions in S. solfataricus CRISPR locus A
Experiment	Mismatches in protospacer 45 or 28 (38 bp)	PCR estimate (kb)	Sequencing result	PCR estimate (kb)	Sequencing result
P1	0	64 bp**	r45–r46 (×3)	4.5	r24–r93
		3.7 (×2)	n.d.	3.8*	r7–r64
		2.7*	r3–r47	6.4*	r2–r103
		2.5 (×2)	n.d.	0 (×2)	n.d. (×2)
		2.2	r40–r69
		1.7 (×2)**	r30–r53
			r22–r47
		0.5	r38–r52
		0 (×5)	n.d. (×5)
P2	1 (+1)	4.7	n.d.	+1, 6.4	n.d.
		0	n.d.	+1	ISC1359 in sp28
				0, 4.4	n.d.
				6	n.d.
P3	1 (+19)	64 bp	r45–r46	3*	r5–r56
		4.2	n.d.	1	r18–r30
		0	n.d.	+1	ISC1359 in sp28
				0* (×2)	n.d. (×2)
P4	1 (+38)	64 bp	r45–r46	0	Spacer present
		0	n.d.	+1	ISC1359 in sp28 (×2)
P5	2 (+1, +38)	n.d.	n.d.	5.3*	n.d.
				4.8*	r26–r103
				0 (×2)	n.d.
				+1	n.d.
P6	5 (+34−38)	3.4	n.d.	2* (×3)	r5–r52
		1.7	n.d.	1*	r5–r52
		0 (×2)	n.d. (×2)	2	r23–r41
				0	n.d. (×1)
P7	8–10 (+29−38)	0 (×9)	Spacer present (×1)	0* (×5)	Spacer present (×1)

CRISPR deletion sizes, or IS element insertions, were estimated from PCR analyses where the results derived from PCR products shown in Fig. 5 are marked by asterisks in columns 3 and 5. ‘0’ means that no deletion was detectable from the PCR product size. ‘Spacer present’ indicates that the CRISPR locus contains the spacer matching the protospacer. n.d. denotes not determined. (×2) shows that the result was obtained independently twice. Transformational efficiencies were low and were estimated at below 3% for the S. islandicus REY15A experiments and in the range 0.1–2.0% for S. solfataricus P2 (see Table 1 legend and Experimental procedures).