? re E. coli DC2 origin

[Dr. S. Shapiro]

Dear Colleauges;

        Does anyone know the origin of
E. coli DC2, a K-12 derivative that was
originally derived from E. coli UB1005?
Was it obtained as a consequence of purpose-
ful chemical or radiation mutagenesis, or
was it simply a spontaneous mutant?

        Responders are kindly asked to con-
tacte m _directly_ at

toukie at zui.unizh.ch

Thanks in advance to all repliers,

S. Shapiro
toukie at zui.unizh.ch