TABLE 1.

Morphological analysis of WT and mutant SIV(Mne) virions

Type of virions	Total no. of virionsa	% of virions
		Immature core	Condensed core			Abnormally largeb	Abnormally smallc
			WT	Rod shaped	Multiple rods
WT	122	2	88	6	4	0	0
ZFI mutation
ZF1 C→S	215	26	17	21	24	12	0
ΔZF1	220	24	14	32	13	17	0
ZF2 mutation
ZF2 C→S	185	30	2	35	19	13	1
ΔZF2	218	28	3	43	11	14	1
Dual mutation
ZF1+2 C→S	153	20	1	44	10	20	5
ΔZF1+2	89	7	1	10	2	26	55

^aTotal number of virions minus those of undefinable morphology. Numbers of virions with undefinable morphologies were not significantly different among all mutant and WT virions observed. 

^bVirions >∼110 nm in diameter. 

^cVirions <∼90 nm in diameter.