Wilkins, Maurice Hugh Frederick WORLD OF MICROBIOLOGY AND IMMUNOLOGY598•
Although a large population of mosquitoes may be pres-
ent, the chances of acquiring West Nile virus via a mosquito
bite is small. Data from the examination of mosquito popula-
tions indicates that less than one percent of mosquitoes carry
the virus, even in areas where the virus is known to be present.
The mosquito to human route of infection is the only
route known thus far. The virus is known to infect certain
species of ticks. However, as of early 2002, tick-borne out-
break of the disease has not been documented in humans.
Person to person contact cannot occur. Even exchange of body
fluids between an infected human and an uninfected person
will not transmit the virus.
Currently no human vaccineto the West Nile virus exists.
Prevention of infection consists of repelling mosquitoes by con-
ventional means, such as the use of repellent sprays or creams,
protective clothing, and avoiding locations or times of the day
or season when mosquitoes might typically be encountered.See alsoViruses and responses to viral infection; ZoonosesWET MOUNT•seeMICROSCOPE AND MICROSCOPY
WHOOPING COUGH•seePERTUSSIS
WILKINS, MAURICE HUGHFREDERICK
(1916-Wilkins, Maurice Hugh Frederick )
New Zealand English biophysicistMaurice Hugh Frederick Wilkins is best known for his work
regarding the discovery of the structure of deoxyribonucleic
acid(DNA). Along with American molecular biologist James
D. Watson(1924– ) and English molecular biologist Francis
Crick(1916– ), Wilkins received the 1962 Nobel Prize in
physiology or medicine for his contributions to the discovery
of the molecular mechanisms underlying the transmission of
genetic information. Specifically, Wilkins’ contribution
involved discerning the structure of DNA through the use of
x–ray diffraction techniques.
Wilkins was born in Pongaroa, New Zealand to Irish
immigrants Edgar Henry, a physician, and Eveline Constance
Jane (Whittaker) Wilkins. Euperior education began at an
early age for Wilkins, who began attending King Edward’s
School in Birmingham, England, at age six. He later received
his B.A. in physics from Cambridge University in 1938. After
graduation, he joined the Ministry of Home Security and
Aircraft Production and was assigned to conduct graduate
research on radar at the University of Birmingham. Wilkins’
research centered on improving the accuracy of radar screens.
Soon after earning his Ph.D. in 1940, Wilkins, still with
the Ministry of Home Security, was relocated to a new team of
British scientists researching the application of uranium iso-
topes to atomic bombs. A short time later Wilkins became part
of another team sent to the United States to work on the
Manhattan Project—the military effort to develop the atomic
bomb—with other scientists at the University of California atBerkeley. He spent two years there researching the separation
of uranium isotopes.
Wilkins’ interest in the intersection of physics and biol-
ogy emerged soon after his arrival to the United States. He was
significantly influenced by a book by Erwin Schrödinger, a
fellow physicist, entitled What is Life? The Physical Aspects
of the Living Cell.The book centers on the possibility that the
science of quantum physics could lead to the understanding of
the essence of life itself, including the process of biological
growth. In addition to Schrödinger’s book, the undeniable and
undesirable ramifications of his work on the atomic bomb also
played a role in Wilkins’ declining interest in the field of
nuclear physics and emerging interest in biology.
After the war, the opportunity arose for Wilkins to begin
a career in biophysics. In 1945, Wilkins’ former graduate school
professor, Scottish physicist John T. Randall, invited him to
become a physics lecturer at St. Andrews University, Scotland,
in that school’s new biophysics research unit. Later, in 1946,
Wilkins and Randall moved on to a new research pursuit com-
bining the sciences of physics, chemistry, and biology to the
study of living cells. Together they established the Medical
Research Council Biophysics Unit at King’s College in London.
Wilkins was, for a time, informally the second in command. He
officially became deputy director of the unit in 1955 and was
promoted to director in 1970, a position he held until 1972.
It was at this biophysics unit, in 1946, that Wilkins soon
concentrated his research on DNA, shortly after scientists at
the Rockefeller Institute (now Rockefeller University) in New
York announced that DNA is the constituent of genes.
Realizing the enormous importance of the DNA molecule,
Wilkins became excited about uncovering its precise structure.
He was prepared to attack this project by a number of differ-
ent methods. However, he fortuitously discovered that the par-
ticular makeup of DNA, specifically the uniformity of its
fibers, made it an excellent specimen for x–ray diffraction
studies. x–ray diffraction is an extremely useful method for
photographing atom arrangements in molecules. The regu-
larly–spaced atoms of the molecule actually diffract the x rays,
creating a picture from which the sizing and spacing of the
atoms within the molecule can be deduced. This was the tool
used by Wilkins to help unravel the structure of DNA.
Physical chemist Rosalind Franklin joined Wilkins in- Franklin, who had been conducting research in Paris,
was adept in x–ray diffraction. Together they were able to
retrieve some very high quality DNA patterns. One initial and
important outcome of their research was that phosphate groups
were located outside of the structure, which overturned Linus
Pauling’s theory that they were on the inside. In another impor-
tant finding, Wilkins thought the photographs suggested a hel-
ical structure, although Franklin hesitated to draw that
conclusion. Subsequently, Wilkins passed on to Watson one of
the best x–ray pictures Franklin had taken of DNA. These
DNA images provided clues to Watson and Crick, who used the
pictures to solve the last piece of the DNA structure puzzle.
Consequently, in 1953, Watson and Crick were able to
reconstruct the famous double–helix structure of DNA. Their
model shows that DNA is composed of two strands of alter-
nating units of sugar and phosphate on the outside, with pairs
womi_W 5/7/03 10:18 AM Page 598