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This Week's Citation | Classic «iis
Bachmann Low KB & Taylor « Recalibrated li ap _—
. Sele Kf Taster Rey, 40:116-67, 1976 ee _ boa
{Yale Univ. School of Medicine, New Haven, CT and Univ. Colorado

MBE R.
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tr ioe

 

 

 

This paper presetits a, ctitical féview of alt

data on thé linkage of genes on the Esche-

Fichia coli K-12 chromosome, a list of genes.

and their functions, and a graphic represen-.

tation of the circular chromosome. [The
SCI* inditates that this paper has been cited

over 1,185 times since 1976.)_

 

Barbara J. Bachmann
Departmént of Human Genetics *
Yale University School of Medicine
New Haven, CT 06510. ;

wee

October 27, 1981

“The series “of finkage maps of |

Escherichia coli K-12 was begun by A.L.
Faylor in 19641 and has served since as
an essential tool in experimental work
directed toward understanding .the
genome of this organism. Early editions
of the ‘map paper’ presented extensive
mapping data.from Taylor's laboratory,

in addition to providing syntheses of all ’

published data, a standardized system
of nomenclature, a list. of gene func-
tions, and a graphic representation of
the chromosome. By 1972, the number’
of gene loci on the map had increased
from 100 to 460. As explorations in
molecular biology came to be focused
to a large extent on this one organism,

the map paper became essential to

many who were not primarily microbial]
geneticists.

. “In 1975, another revision of the map
was badly needed and Taylor realized
that he could not spare the time re-
quired to continue the series. It seemed
reasonable for me to take over the re-
view because, as curator of the E. coli
Genetic Stock Center, | need to keep
track of all of the loci on the map in
order to respond to ‘requests for strains.

Taylor agreed to assist with this edition, ©

 

 

 

and Came to Yale to hétp inthe analysis
of the data. ee

“First, Brooks Low recalibrated the
map, which is still based on the time-of-
entry of markers by conjugation, using
the large set of Hfr Strains which he had
assembled —and many of which he had
isolated. To our surprise and. delight,
the result was a 100-minute map (which
is so convenient a figure that some
have assumed that this length was

chosen arbitrarily), This map paper con-

=

tained around 680 gene loci and a bibli-
ography of 763 citations. Obviously,

_ Rot every person using £. col could af-

“ford to perform’ this Synthesis for
- himself. dt is the drawing,

. the bibliog-
raphy, and the table of gene functions
that are most often used. Apparently,
few people read the text, which con.
tains many qualifications and exhorts
the reader to consult. the original
literature.

_» “I later came. to appreciate Taylor’s

many reasons for. wishing to relinquish
thistask. Each time the map is drawn it.
is necessary to.go over all data ever
published and to reconcile the widely:
varying, and sometimes conflicting,
results obtained in different, Jaborato-
ries. It_is also necessary to arbitrate

“disputes regarding:gene symbols. Con-.

structing the map is one way to offend
a great many people simultaneously.
When the entire map is fitted together, -

_ almost no gene is put exactly where

any one person said it was and the posi-
tion is seldom. precisely-known.:° os
“I revised the map again in 19803
with the generous assistance-of a great
‘many of the authors of the data; and
Low contributed a review of mapping
techniques. The fiumber of gene loci
mapped has continued to increase lin-
early with time. The 1980 edition con-
tains almost 1,000 -loci, representing ©

: possibly -elose to ‘one quarter of the
Benes of the ‘best known of all

organisms.”

1, Taytor AL & Thoman M S. The genetic ‘map of Escherichia coli K-12. Genetics 50:659-77, 1964,
. [The SC/ indicates that this Paper has been cited over 205 times since 1964.}
2. Taylor A L & Trotter CD, Linkage map of Escherichia coli strain K-12; Bacteriol, Rev. 36:504-24, 1972, .
[The SCJ indicates that this paper has been cited over 665 times since 1972.)
3. Bachwana BJ & Low K B. Linkage map of Escherichia coli K-12, edition 6.
_ + Microbiol.-Rev. 44:1-56, 1980.-[The SET indicates that this paper tas beeti:cited over 200 times sthce 1980.) -

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Ls CURRENT CONTENTS”

~ 1982 by tsi"