Chromosome Mapping of Pasteurella Pseudotuberculosis by Interrupted Mating
FORT DETRICK FREDERICK MD
Pagination or Media Count:
Pasteurella pseudotuberculosis containing the plasmid Flac transferred its chromosome from a specific origin in an oriented manner to five multiply auxotrophic strains of P. pseudotuberculosis. In a mating system containing gelatin, glucose, and phosphate buffer, a maximum of 0.1 of the donor cells transferred lead markers. The donor population was counterselected with nalidixic acid. P. pseudotuberculosis containing the plasmids FCM, F13, or Fhis donated markers in the same order and with approximately the same entry times as did the standard Flac donor strain, suggesting that F itself has enough homology with a specific region on the chromosome of P pseudotuberculosis to mobilize the chromosome. We have established the entry time in minutes after mixing parental cultures of seven markers as follows proline 10 minutes arginine 14 minutes histidine 14 minutes threonine 25 minutes lysine 50 minutes tyrosine 67 minutes and tryptophan 77 minutes. The resulting chromosome map shows a marked similarity both in relative order and in distance between markers to the well established chromosome map of Escherichia coli.