TABLE 3.

Virus production by cells expressing NC mutants together with Δp12 MLV^a

Particle type	% Pelletable mature virions	IU/ml
Wild type	100	106 ± 5 × 104
Δp12 + NC(Δ16-23)	94 ± 37	8.5 × 104 ± 4 × 103
NC(Δ16-23)	3 ± 2	<1.5 × 103
C37- (or C60-)	<0.5	<1.5 × 103
Δp12 + C37-	56 ± 6	1.5 × 104 ± 2 × 103
Δp12 + C60-	34 ± 8	6 × 103 ± 5 × 102
Δp12 alone	11 ± 8	<1.5 × 103

^aThe amount of mature particle release was evaluated by measuring p30^CA by immunoblotting. Results are averages from three independent experiments; the amount released by wild-type MLV was set at 100%. Infectivity was measured by GFP transduction as described elsewhere (30).