Retention or viral antigen in the cytoplasm of cells infected with temperature-sensitive mutants of an avian adenovirus.

Immunofluorescent studies were made on chicken kidney cell cultures infected with various temperature-sensitive (ts) mutants of an avian adenovirus, chicken embryo lethal orphan (CELO), which grow well at the nonrestrictive temperature of 31 degrees , but fail to grow at the restrictive temperature of 40 degrees . At 40 degrees some mutants (ts 5, 8, and 10) accumulated viral antigen in the cytoplasm, but scarcely at all in the nucleus. However, at 31 degrees they accumulated the antigen in the nucleus like the wild-type strain at either 31 degrees or 40 degrees . These mutants seemed to complement each other in nuclear accumulation of antigen at 40 degrees . In cells infected with ts 8, the antigen remaining in the cytoplasm during incubation at 40 degrees was partially transferred to the nucleus even in the presence of an inhibitor of protein synthesis when the temperature was lowered to 31 degrees . The results suggest that viral antigen produced in the cytoplasm is transported to the nucleus and that these ts mutants are defective in this process at 40 degrees .There are apparently two other types of ts mutant: one type (ts 3, 7, and 12), like the wild-type strain, showing nuclear accumulation of antigen at 40 degrees and the other (ts 6, 11, and 17) showing no, or only slight, formation of the antigen at 40 degrees .