A number of mutants of E. coli K 12, deficient in purine biosynthesis, have been isolated and
the biochemical blocks have been determined. The mutations were mapped in conjugation …

A variable delay among mating pairs in the time between contact formation and the initiation
of F transfer was found. The conjugation process has no effect on the multiplication of the …

Acridine orange does not interfere with the distribution of the F-particles among the daughter
cells but inhibits the multiplication of the episome.In growing cells the generation time of the …

In studies of chromosome transfer in mating pairs formed during a 5-minute period of contact
between Hfr and F- cells under conditions which precluded the formation of new pairs, it …

Following a brief description of its background and content, the Dutch Decree on Genetically
Modified Organisms is discussed in relation to: (1) other legislation, in particular the …

Motile recombinants may be obtained by crossing Escherichia colt strain K12, F +, with the
non-flagellated strain E. coli strain B, F −. The flagella of the recombinants have the same …

Two types of mutants of Aerobacter aerogenes were obtained which grow anaerobically in
a minimal medium with glucose as sole carbon source, but which require either succinate or …

R factors, responsible for transmissible drug resistance in Enterobacteriaceae, convert their
hosts into donors of genetic material, but fewer recombinants for chromosomal genes are …