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Name: Sumathi
Status: Student
Grade:  Other
Location: AL
Country: United States
Date: June 2006


Question:
What is mean by time mapping in microbial genetics?



Replies:
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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