mreD cells was not a secondary effect of their spheroidal shape came from study of a pbp2ts strain which, when grown under nonpermissive conditions
, also undergoes a rod-to-sphere transition.
The earliest literature has offered support and a rationale for providing counseling services under nonpermissive conditions
(Arbuckle & Boy, 1961; Beier, 1952; Gometz & Parker, 1968; Snoxell, 1960).
Comparison of the permissive and nonpermissive conditions
allows the identification of mutants that drop out (that is, do not grow) under nonpermissive conditions