Fertility regulation in F-like resistance transfer factors.

ABSTRACT

Mutants of the R factor R100 have been isolated that mediate high-frequency transfer of the R factor during conjugation. Complementation tests revealed two classes of mutants, operator-constitutive and repressor-negative. Some of the latter class were suppressible by amber and ochre suppressors. The results support a simple model of regulation for the control of R-factor-mediated piliation.