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Biomedical subjects

J Cullum

Publications and source records attributed to J Cullum.

42 records · Page 3Linked to original sources
PubMed1979

Recipient competence in F'lac matings of Escherichia coli K-12.

We studied recipient mating ability in the presence of excess F'lac donors. Ninety-five percent of recipients were able to receive F'lac in 30-min matings. Competition between an F'-lac donor and an F'lac traI donor, which mobilized a ColE1 derivative (pML2), showed that each recipient mated with an average of two to three donors in 30 min. Experiments in which the competing donor was added at different times showed that some competition occurred throughout the 30-min mating period, which suggested that aggregate formation was spread over this time.

Conjugation, Genetic↗
PubMed1978

Cell growth and length distribution in Escherichia coli.

The length growth rate of an exponentially growing population of Escherichia coli B/r was calculated from the population length and birth length distributions. Cell elongation took place at a constant rate that doubled at a certain length. This change in rate was responsible for a sudden drop in the frequency of classes of cells longer than that length. Asymmetry in cell partition was able to generate cells both shorter and longer than the expected twofold range, but did not greatly modify the length distribution in between.

Computers↗
PubMedDate not supplied

The lactose transposon Tn951: characterization of transposition.

Transposition of the lactose transposon Tn951 was found to still occur in the absence of its original host plasmid pGC1. Transposition was recA-independent. These results show that Tn951 is indeed a transposon. A computer program was developed to facilitate mapping of transposon integration sites in plasmids from restriction data.

DNA Transposable Elements↗