TABLE 3.
Quasispecies composition in the V3 and V4 regions of the env gene of the 15 primary FIV isolates examined, grouped by sensitivity to cross-neutralization, and the genetic polymorphism of the tissue culture-adapted FIV-Pet
| Category of virus | Sensitivity to cross-neutralization | Isolate | No. of
variantsa
|
|
|---|---|---|---|---|
| V3 region | V4 region | |||
| Primary | High (neutralized by ⩾30% of test sera) | M19 | 11 | 3 |
| M45 | 10 | 4 | ||
| M64 | 11 | 8 | ||
| M73 | 10 | 8 | ||
| M88 | 11 | 3 | ||
| M89 | 10 | 2 | ||
| Mean ± SD | 10.5 ± 0.54b | 4.6 ± 2.65 | ||
| Low (neutralized by ⩽10% of test sera) | M2 | 7 | 9 | |
| M3 | 6 | 23 | ||
| M17 | 8 | 7 | ||
| M22 | 13 | 9 | ||
| M26 | 9 | 8 | ||
| M82 | 6 | 6 | ||
| M91 | 4 | 7 | ||
| M92 | 5 | NDc | ||
| M97 | 6 | 2 | ||
| Mean ± SD | 7.1 ± 2.66 | 8.8 ± 6.12 | ||
| Tissue-culture adapted | High | Pet | 2 | 3 |
a
Variants detected in at least two independent assays.
b
Significantly different from the low-sensitivity group (P < 0.01, Student’s t test).
c
ND, not done.