FIG. 3.

The nuclease Dns degrades extracellular DNA. Crab shell fragments immersed in DASW medium were inoculated without bacteria (control; lane 1) or with V. cholerae A1552 (WT; lane 2), A1552Δdns (lane 3), A1552ΔluxO (lane 4), and A1552ΔhapR (lane 5), respectively. Donor gDNA (2 μg) was added immediately at the time of inoculation; DNA was recovered from the supernatant after a 2-hour incubation period and visualized on an agarose gel. Undegraded donor gDNA (arrow) and degradation products (bar) are shown. Lane L, 1-kb DNA ladder (Invitrogen).