The effect on recombination of mutational defects in the DNA-polymerase and deoxycytidylate hydroxymethylase of phage T4D.

XPERIMENTS will be described which show that in the presence of mutaE tions in genes 43 arid 42 of phage T4D (EPSTEIN et al. 1963) recombination is increased several-folld. Gene 43 has been identified as the structural gene of DNApolymerase (DE’WAARD and LEHMAN 1965; WARNER and BARNES 1966). Gene 42 has been shown to specify dCMPl-hydroxymethylase (DIRKSEN, HUTSON and BUCHANAN 1963; WIBERG and BUCHANAN 1964).