FIG. 1.

Effects of deletions on autonomous replication of ars2004. Derivatives of pARS2004 with nested unidirectional deletions were constructed as described in Materials and Methods. Plasmid DNA was introduced into S. pombe HM123 cells, and the number of Leu⁺ colonies was scored after incubation for 4 days at 30°C. The transformation efficiency relative to the value for the parental pARS2004 was determined. Regions retaining the natural sequence in the deletion derivatives are shown by lines on the top. Series N and X constructs contain deletions from the left and right ends of the insert, respectively. Series HD constructs are series N derivatives lacking the region right of position 1741. Transformation efficiencies of deletion derivatives in series N (filled circles), series X (open circles), and series HD (open squares) relative to that of the parental plasmid pARS2004 are shown with standard deviations.