Obituary: Emeritus Professor Brian M Wilkins
Brian Wilkins used genetics to study mechanisms controlling the horizontal spread of genes in bacterial populations. His work was of great intrinsic interest as a study of complex biological phenomena, but also had broader impact in revealing mechanisms driving the spread of antibiotic-resistance in bacterial populations and events in important infectious diseases.
a brief period at Queen Mary College, London, Wilkins joined the laboratory of
Paul Howard-Flanders in the Radiobiology Laboratories, Yale University School
of Medicine, as a postdoctoral research associate. Howard-Flanders was a British-born geneticist who was established
amongst the international network of scientists interested in the mechanisms
of replication, recombination and repair of DNA molecules.
Together with Dean Rupp and others, they published several important
papers on the replication and recombination of bacterial DNA that had been
damaged by UV irradiation.
In 1969, Wilkins was recruited by Bob Pritchard to join the emerging new Department of Genetics at the University of Leicester. There he continued to work on processes related to DNA recombination, with increasing emphasis on the role of plasmid-borne genes in the transfer of DNA between bacterial cells. As early as 1975 he produced evidence for a genetic interaction between certain plasmid genes and host genes encoding components of the cellular DNA replication machinery.
of this observation in his laboratory led to the discovery of a plasmid gene
encoding DNA primase, an enzyme crucially involved in the initiation of DNA
replication. Wilkins and his colleagues
established that the plasmid-specified primase protein was transferred from
the donor to the recipient cell during the bacterial ‘mating’ event, and
that this could occur in the absence of DNA transfer.
The importance of these observations on plasmid-mediated protein export
is emphasised by the genetic homology between the cognate transport proteins
and components of secretion systems associated with several clinically
important bacterial pathogens, including Legionella
pneumophila, the cause of Legionnaires’
Wilkins’ interest in plasmid biology and horizontal gene-transfer fuelled a continuing study of the genetic interactions between the plasmid and the recipient cell, in which the newly transferred DNA encounters a potentially antagonistic environment. He pioneered the studies that have shown that the first few plasmid genes transferred are immediately expressed in the recipient cell to produce proteins that help to protect and establish the incoming DNA in the hostile environment. Plasmid-encoded proteins block host-specific degradation (‘restriction’) of the incoming DNA, inhibit the potentially suicidal ‘SOS’ response and augment a potentially limiting host protein that is necessary for DNA replication. The relevant plasmid genes are expressed in a transient burst by a mechanism that unusually involves utilisation of the single-stranded transferred DNA as the template for RNA polymerase.
most recent studies, in collaboration with biochemical colleagues, involve
exploration of the hypothesis that the single-stranded DNA folds into a unique
secondary structure that creates a temporary template for RNA polymerase.
Replication of the transferred strand in the recipient would
necessarily destroy this special secondary structure and self-limit the burst
Wilkins’ approach to laboratory investigation was reflective and careful. He relished the planning process, designing the controlled experiment that would test the current hypothesis. Early in his career a referee assessed him as ‘interested, original, ingenious and effective’: that perceptive description remained true throughout his career. He worked with a small team, often a technician and a PhD student, sometimes a single postdoctoral associate, but was able to make an internationally recognised scientific contribution over two decades.
status in the field was well recognised. He
received frequent invitations to speak or chair sessions at international
meetings and to write reviews for leading journals.
He was also a very effective university teacher, caring deeply about
the welfare of his students and the quality of their educational experience.
He was an effective and painstaking administrator and had an
integrating influence on his beloved Department of Genetics while acting as
Head of Department from 1996 to 2000.
Wilkins had productive interactions with a wide circle of professional
colleagues in Europe, Australia and North America, whom he referred to as his
‘friends’. He was magnanimous in
his relationships and seemed constitutionally incapable of making enemies.
Michael Wilkins, academic and research scientist: born Cheltenham, April 3,
1939; Assistant Lecturer and Lecturer, Queen Mary College, London, 1965-66;
Research Associate, Radiobiology Laboratories, Yale University School of
Medicine, USA, 1966-69; Lecturer, Department of Genetics, University of
Leicester, 1969-80; EMBO Research Fellow, Max-Planck-Institut für Molekulare
Genetik, Berlin, 1980; Senior
Lecturer, University of Leicester, 1980-96; Reader, 1996-2000; Personal Chair
in Microbial Genetics, 2000-2003. Head of Department of Genetics, University
of Leicester, 1996-2000. 1972, married
Susan Hollom; one son. Died April 7,
Last updated: 16 May 2003 15:00
Maintained by: Barbara Whiteman
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