Extragenic Suppression of a ts Phenotype During Recombination Between ts Mutants of Two Fowl Plague Virus Strains with a ts Mutation in Gene 1

Isolation and Classification of Temperature‐Sensitive Mutants of Influenza B Virus

“…However, ts9 and ts18-409 produced active HA and NA and ts13 also produced active NA. The similar phenomenon has been observed with ts mutants of influenza A viruses (5,9). One possibility is that small amounts of mRN A transcribed as a result of a low degree of leak or because of an unimpaired primary transcription even in the absence of amplification, is sufficient to code for detectable levels of gene products, as pointed out by Sugiura et al (9).…”

Studies of Fowl Plague Virus Temperature-sensitive Mutants with Defects in Synthesis of Virion RNA

“…These data indicate that extragenic suppression of FPV ts mutants may occur not only between two different FPV strains (Ghendon et al, 1982a) but also between two ts mutants qf the same strain.…”

“…However, mutant ts 166 readily complemented and recombined with mutants ts 43 and ts 29 (Ghendon et al, 1982a) containing a ts mutation in gene I, as well as with mutant ts 44 also having a ts mutation in gene 1 (Ghendon et al, 1982a) and obtained from the Cambridge collection (Mahy, 1983). These data suggested that in this mutant the ts mutation was located in gene 3 coding for the polypeptide PA. Data presented in Table 4 show that none of the 47 clones isolated from the population which had resulted from recombination of the ts ÷ recombinant R166/29 with wild-type FPV possessed a ts phenotype.…”

“…These data suggest that the temperaturesensitive phenotype of mutant ts 43 is due to a ts mutation in gene 1 coding for polypeptide PB2. <0.001 * The recombination test was carried out as described previously (Ghendon et al, 1982a). The gene assignment of mutants ts 29, ts 131, ts 5 and ts 303/l has been reported previously (Ghendon et al, 1982b(Ghendon et al, , 1983a.…”

“…We also revealed extragenic suppression of a ts phenotype during recombination of two ts mutants of FPV Weybridge and Rostock strains having a ts mutation in the same gene (gene 1) (Ghendon et al, 1982a). In view of this we decided to study whether or not extragenic suppression occurs during recombination of mutants ts 29 and ts 43.…”