Allan McCulloch Campbell (April 27, 1929 – April 19, 2018) was an American microbiologist and geneticist and the Barbara Kimball Browning Professor Emeritus in the Department of Biology at Stanford University. His pioneering work on Lambda phage helped to advance molecular biology in the late 20th century. An important collaborator and member of his laboratory at Stanford University was biochemist Alice del Campillo Campbell, his wife.
Education
Campbell earned his bachelor's degree at the University of California, Berkeley (1950) and master's (1951) and doctoral (1953) degrees from the University of Illinois where he worked with Sol Spiegelman.
Career
From 1953-1957 Campbell was on the faculty of the University of Michigan. During the summers he spent time with Gio ("Joe") Bertani at Caltech and the University of Southern California, at Cold Spring Harbor Laboratory and at the Institut Pasteur with François Jacob.
In 1958 he married Alice del Campillo, a Ph.D. student in biochemistry at the University of Michigan. They spent their honeymoon year working in Paris. The two worked closely together throughout their careers, investigating research questions such as the encoding of heat-sensitive endolysin and the biosynthesis and regulation of biotin.
Campbell spent the next nine years on the faculty of the University of Rochester, where he made significant discoveries about lambda phage.
In 1968 Campbell joined the Department of Biology at Stanford University, where he led his own laboratory. He was appointed to the Barbara Kimball Browning endowed chair in 1992.
Campbell was the editor of the Annual Review of Genetics from 1985 to 2012.
Research
Campbell's research has concentrated on the genetics of bacteria and their viruses, especially the integration of viral DNA into host chromosomes. His most prominent discovery was the proposal of the “Campbell model” of virus insertion, where viral DNA is inserted into the host chromosome, becoming covalently bonded to the bacterial DNA, and then remains dormant until activation. Campbell's research was focused on a specific bacterial virus, phage lambda, and its host bacterium E. coli, but the model provided insights into how extrachromosomal DNA can be inserted and excised in other organisms.
This model was proposed in the book Episomes published in 1968, the first comprehensive treatment of plasmid biology. It was described as "a wide-ranging and critical evaluation of the experimental foundation of the episome concept".
While study of the regulation of integration and excision of phage lambda in E coli has been a primary focus of his research, Campbell and research associates also studied regulation and expression of E coli genes linked to the lambda insertion location, including the biotin (bio) and galactose (gal) genes.
Background on phage lambda and lysogeny
Early studies on bacterial viruses began after the discovery by Twort and d’Herelle of ‘filterable agents’ which were able to destroy bacteria. These were demonstrated by creating a lawn of bacteria on appropriate media, mixing with these ‘filterable agents’ and then observing areas of destroyed cells seen as cleared circular areas (plaques) on the lawn. These plaques were interpreted as the result of a single agent infecting a bacterial cell, reproducing in the cell and then bursting open to infect surrounding cells, repeating the process until a clear circular area of destroyed cells becomes visible to the unaided eye. These filterable agents were named bacteriophages (eaters of bacteria) or phage for short.
The 1940s produced the first pictures of bacterial viruses using electron microscopy produced the first photos of bacterial viruses, and research on the mechanism of infection and reproduction dramatically increased. One of the focal points of this research was Cold Spring Harbor Laboratory on Long Island, where a ‘phage group’ led by Salvador Luria, Max Delbrück, Alfred Hershey and others met in the summers for research and training of new investigators.