Plasmids residing in UT26DB and its transconjugant UT26DBT1. Gel electrophoresis of plasmids (a) and Southern blot analysis with the linB gene as a probe (b) are shown. Lanes 1, UT26DB; lanes 2, UT26DBT1. The white arrowheads indicate endogenous plasmids pCHQ1 (185 kb), pUT1 (30 kb), and pUT2 (5 kb), respectively. The black arrowhead indicates pLB1.