%0 Journal Article %A Witmer, H. %A Baros, Anna %A Forbes, Janet %A Padnos, Donna %A Maricondia, W. %A Weiner, M. %T Transcriptional Control of T4 Coliphage-Specific Genes 30, 42, 43, rIIA, rIIB, and e %D 1976 %J Journal of General Virology, %V 31 %N 3 %P 289-302 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-31-3-289 %I Microbiology Society, %X SUMMARY Escherichia coli b/r (su 0) was infected, at 30 °C, with T4Dam +, T4DamB24amN82 (1 -, 44 -, DNA-negative phenotype), and T4DamN134amBL292 (33 -, 55 -, maturation-defective phenotype). A genetic (‘transformation’) assay was used to monitor transcription of genes 30 (polynucleotide ligase), 42 (deoxycytidylate hydroxymethylase), 43 (DNA polymerase), rIIA, rIIB, and e (endolysin). The principal results are: (1) All of the genes studied were transcribed exclusively from the so-called l-strand of phage DNA. (2) DNA synthesis and the maturation-defective proteins were required to turn-off transcription of genes 42, rIIA, tIIB, and 43. Experiments performed with chloramphenicol suggested that all phage-specific proteins required to turn-off transcription of these genes were not present until 6 to 8 min post infection (p.i.). (3) During a normal developmental programme, gene 30 was transcribed throughout the eclipse. DNA-negative and maturation-defective conditions had no obvious effect on transcription of this gene. (4) During a normal lytic event, two discrete waves of gene e transcription were observed. The late wave was dependent upon DNA-synthesis and presence of functional maturation-defective proteins. The early wave was unaffected by DNA-negative or maturation-defective conditions. Experiments with chloramphenicol indicated that, if any virus-specific proteins are involved with regulation of early e transcription, such proteins are present by 3 min p.i. The data are interpreted to mean that early gene transcription is regulated by a minimum of two mechanisms. One of these mechanisms is fully operational by the 3rd min and, among the genes studied, controlled early e transcription. A second mechanism becomes operational between 6 and 8 min p.i. and controls transcription of genes 42, 43, rIIA, and rIIB. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-31-3-289