Table 3. Group II intron fragments, number of potential homing sites available in their host genomes, and proportion of homing site occupation.

Group II intron	Host genome	Fragmentnumber	Availablehoming sites*	Proportion ofoccupation (%)
E.c.I9	E. coli BL21	1	4	20
	E. coli BL21_DE3	1	4	20
	E. coli REL606	1	5	17
	E. coli IAI1	1	3	25
	E. coli SE11	1	6	14
	E. coli E24377A	1	3	25
	E. coli EDL933	1	2	33
	E. coli Sakai	1	2	33
	E. coli EC4115	1	2	33
	E. coli TW14359	1	2	33
E.c.I3	E. coli E24377A	1	6	14
	S. sonnei Ss046	3	0	100
	S. boydii Sb227	3	1	75
	S. boydii SbCDC3083	3	1	75
	S. flexneri Sf301	3	0	100
	S. dysenteriae Sd197	3	0	100
E.c.I4	E. coli BW2952	1	1	50
	E. coli DH10B	1	1	50
	E. coli MG1655	1	1	50
	E. coli W3110	1	4	50
	E. coli SMS_3_5	1	10	9
	E. coli UTI89	1	3	25
	E. coli UMN026	1	7	13
	S. sonnei Ss046	1	15	6
	S. boydiii SbCDC3083	1	57	2
	S. flexneri Sf301	1	43	2
	S. dysenteriae Sd197	1	25	4
So.gl.I1	S. glossinidius 'morsitans'	2	76	3
c-Ha.de.I1 (subgroup 1)	H. defensa 5AT	1	49	2

^*: at the expected time of fragment acquisition (i.e. including homing sites currently occupied by full-length copies).