TABLE 2.
Restriction endonuclease analysis of the viral isolates
| Virus passagea | Presence of minigenomeb | Phenotype of the
virus
|
||
|---|---|---|---|---|
| No. of clones with the genotype indicated in the next columnc/total no. of clones | Restriction endonuclease susceptibility at
positionc:
|
|||
| S 622 | S1208 | |||
| PTV + M54-Sc11 | + | 12/12 | PTV | PTV |
| PTV + M54-Sc11-SW1 | ND | ND | ND | ND |
| PTV + M54-Sc11-SW1-ST1 | − | 29/29 | C11 | C11 |
| PTV + M54-Sc11-SW1-ST2 | − | ND | ND | ND |
| PTV + M54-Sc11-SW1-ST3 | − | 12/20 | C11 | C11 |
| 8/20 | PTV | PTV | ||
a
The numbers after SW and ST indicate the passage numbers given in swine or ST cells, respectively.
b
The presence of the minigenome was determined by Northern blot and RT-PCR analyses. ND, not determined.
c
cDNAs derived from the S gene of TGEV strain PTV have MslI and DraIII restriction endonuclease sites at nt 1208 and 1252, respectively. cDNAs derived from clone C11 have two DraIII sites at nt 622 and 1252 and no restriction site susceptible to MslI. PTV and C11 indicate restriction endonuclease patterns identical to cDNA derived from the TGEV strains PTV or C11, respectively. ND, not determined.