UV sensitivity of several genetic markers of Haemophilus influenzae DNA.

Studies on inactivation by UV of several genetic markers of the streptomycin and novobiocin resistance regions of H. influenzae DNA have shown that two kinds of markers may be found with respect to frequency of integration, UV sensitivity and reactivability. One class of markers has high integration frequency and low UV sensitivity, which can be partly explained by the reactivability of the irradiated markers. The second class of markers has low integration frequency and high UV sensitivity. Markers of each class have been found in the novobiocin region.-In one recipient strain with decreased transformability the difference in integration frequency between the two classes is enhanced.