Country: United States
Date: June 2006
What is mean by time mapping in microbial genetics?
When two strains of E. coli with the appropriate mating type are mixed (for
example F- and Hfr), the bacteria conjugate and the Hfr DNA molecule breaks
at a specific location and the DNA molecule is slowly transferred from the
Hfr cell to the F minus cell. At various times, the cells are separated by
agitating them in a Waring blender and the resulting progeny are analyzed by
which genes have been transferred. The length of time between when two
different genes are transferred is a direct measure of how far apart they
are on the DNA molecule. This distance or time of transfer can be used to
construct a genetic map of the bacterial chromosome.
Ron Baker, Ph.D.
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Update: June 2012