TABLE 6.

Homologous recombination within IS elements

IS element	No. of sequences	No. of variable sites	No. of informative sites	Mean shuffled h	h ratioa
IS607AB	44	61	40	89.2	0.217
Group Ia	7	NDb	ND	ND	ND
Group Ib	11	26	14	17.7	0.348
Group II	19	59	39	119.2	0.525
IS605ABc	42	67	53	261.9	0.558
GroupI	10	41	18	19.2	0.654
GroupII	14	54	39	90	0.701

^aThe h ratio is the average of h ratio assuming high, low, and medium expression.

^bND, not determined due to insufficient number of synonymous variable sites.

^cIS605 group designations are based on the split decomposition analysis shown in Fig. 3C.