1 2/16/10 Bacterial chromosome mapping As we ... - Biology Major

neighboring fraction of the entire chromosome. For this reason, as for F’ duction,specialized transduction is of limited mapping value.In contrast, in generalized transduction, any chromosome fragment of one cell can beincorporated into the head of a lytic phage and thereby potentially be transferred toanother cell. Since any fragment can be passed, the entire bacterial chromosome can besampled and thereby mapped. For this reason, generalized transduction has proven quiteuseful for mapping the entire bacterial chromosome.Similarly, transformation behaves like generalized transduction and has therefore been ofvalue for mapping the entire bacterial chromosome. In transformation, any chromosomefragment can be picked up by another cell, thus any chromosomal region can berecombined in the new cell. As for generalized transduction, then, transformation cansample and thereby map the entire bacterial chromosome.To recap, Hfr conjugation has proven useful for generating general maps of the entirebacterial chromosome. In turn, generalized transduction and transformation have provenuseful for adding details about the entire bacterial chromosome to these maps. Incontrast, F’ duction and specialized transduction have been of limited utility, since theyinvolve only DNA regions around the integration sites of the F plasmid and the lysogenicphage, respectively.2