TABLE 1.

Fitness values of clones after 15 plaque-to-plaque transfers and 1, 5, and 10 large population passages

Clonea	Fitness value				Maximal fitness increasec
	Final plaque-to-plaque populationb	Large population passage
		1	5	10
D	1.23	NDf	1.57	NDd,f	0.34 (+28)
K	1.54	NDf	1.70	2.5	0.96 (+62)
I	1.61	NDf	1.32	5.64	4.03 (+250)
G	<0.001e	1.73	1.61	1.78	1.78 (+178,000)

^aThe origins of the HIV-1 clones are detailed in Materials and Methods and were described previously (48).

^bAll clones were plaque passaged 15 times, except for clone G, which went to extinction in passage 7.

^cMaximal fitness increases were determined between the plaque-to-plaque and large population passages. The values used for the comparison are marked in bold. Values in parentheses are percentages for all clones.

^dWe were unable to determine the fitness of clone D15p10. This clone displayed a mixture of variants, and the HTA after the competition passages could not be analyzed.

^eLimit of detection (see Materials and Methods).

^fND, not done.