EFFECT OF INTERSPECIFIC TRANSFORMATION ON LINKAGE RELATIONSHIPS OF MARKERS IN HAEMOPHILUS INFLUENZAE AND HAEMOPHILUS PARAINFLUENZAE.

Nickel, Lois (University of Pennsylvania, Philadelphia), and Sol H. Goodgal. Effect of interspecific transformation on linkage relationships of markers in Haemophilus influenzae and Haemophilus parainfluenzae. J. Bacteriol. 88:1538-1544. 1964.-Highly competent cells of Haemophilus parainfluenzae were obtained by a modification of the aerobic-"anaerobic" method of Goodgal and Herriott. The mutant markers for streptomycin and novobiocin resistance in H. parainfluenzae were shown to be unlinked. These same markers were transferred into H. influenzae in two transformation steps, and the deoxyribonucleic acid (DNA) was extracted. Transformation of recipient H. influenzae with DNA from the latter showed the markers to be linked, and transformation of recipient H. parainfluenzae with this DNA showed that the markers were not cotransferred. The linked streptomycin- and novobiocin-resistance mutations of H. influenzae were transformed into H. parainfluenzae in two stages, and the DNA was extracted. Transformation of recipient H. parainfluenzae with this DNA demonstrated the markers to be unlinked in H. parainfluenzae. When these markers, originally from H. influenzae and present as unlinked factors in H. parainfluenzae, are transferred back into H. influenzae, the markers showed their original linkage. The novobiocin- and erythromycin-resistance markers of H. influenzae were unlinked in H. influenzae, but were linked when transferred into H. parainfluenzae. The erythromycin-resistance marker of H. influenzae, when transferred into a novobiocin-resistant mutant of H. parainfluenzae, showed linkage with it. Evidence is presented to show that H. parainfluenzae streptomycin and novobiocin markers are homologous to streptomycin and novobiocin markers in H. influenzae.