1022-7954/02/3808- $27.00 © 2002
Russian Journal of Genetics, Vol. 38, No. 8, 2002, pp. 984–987. Translated from Genetika, Vol. 38, No. 8, 2002, pp. 1163–1166.
Original Russian Text Copyright © 2002 by Bogdanov.
In 2002, there was the 100th anniversary of the birth
of Barbara McClintock (1902–1992), a world-
renowned geneticists and cytogeneticist, the discoverer
of transposable elements, author of many other classi-
cal cytogenetic works, and Nobel Prize winner.
McClintock’s discovery of transposable elements of
the genome in 1951 opened a new epoch in genetics.
Some publications on this theme state that McClintock
demolished the dogma of the constancy of the genome
created by T.H. Morgan and his followers. More cor-
rectly, McClintock complemented the postulate on the
constant linear arrangement of genes on chromosomes,
which was put forward by Morgan’s school, by the discov-
ery of the previously unknown class of genetic elements
capable of moving within the genome, incorporating into
the vicinity of ﬁxedly located genes or into the genes
themselves, and causing their mutations. The main postu-
lates of Morgan’s theory held but the views on the organi-
zation and function of the genome have changed. The
functions and modes of inheritance of transposable ele-
ments proved to be fundamentally different from those of
classical genes studied by Mendel and Morgan.
McClintock discovered transposable elements
(transposons) in maize. A decade after this discovery,
transposons were found in bacteria, and, after another
17 years, in
. This succession of discoveries
provided the basis for the concept of genome instabil-
ity. An idea appeared on the “horizontal” transmission
of genes under natural conditions. This has caused a
impact on the theory of evolution.
Why did McClintock and not another researcher
discover transposable elements of the genome? Why
were these elements ﬁrst discovered in maize, and only
afterwards were similar phenomena found in bacteria
, more “convenient” genetic objects? To
answer these questions, we should year by year follow
the development of McClintock’s studies and take into
account their historical background.
Barbara McClintock was born on June 16, 1902, in
Hartford, Kentucky, United States, in a doctor’s family.
She graduated from the College of Agriculture of Cor-
nell University in Ithaca, New York, in 1923 and
received her Ph.D. degree in botany there in 1927. Hav-
ing been appointed to a professorship at the same col-
lege, she began intense research work. McClintock
worked at Cornell University, with intermissions, until
1936. In the same period, she won scholarships to post-
graduate training at the laboratories headed by L. Sta-
dler and T.H. Morgan (in the United States) and
R. Goldschmidt (in Germany). McClintock left Ger-
many in 1934, before the scheduled end of her training,
because conditions for her research became unfavor-
able when the Nazis came to power. She returned to the
United States and, while waiting for a vacancy, worked
without salary for nine months.
From October 1934 to 1936, McClintock worked at
Cornell University again. In 1936–1941, she was an
assistant of L. Stadler at the University of Missouri. In
1941–1967, McClintock was a personal researcher at
Carnegie Institution with a ﬁxed workplace at the Cold
Springs Harbor Biological Station, where she settled
when she retired.
According to her biographer Evelyn F. Keller,
McClintock’s development as a researcher was already
completed in the ﬁrst years of her work at the labora-
tory headed by Professor R.A. Emerson in Ithaca. In the
late 1920s, a group of talented young researchers was
formed around Emerson. In this group, George W. Bea-
dle (who afterwards won the Nobel Prize for his studies
) and Marcus M. Rhoades (a future clas-
sic of the genetics and cytogenetics of maize) were the
Life Devoted to Science
(In Commemoration of the 100th Anniversary
of the Birth of Barbara McClintock)