Pic1 is required for the survival of <i>trt1Δ</i> cells having circular chromosomes.

<p>(A) <i>trt1Δ pic1-T269</i> cells were streaked on YEA+FUDR plates to select for cells that could grow after the loss of plasmid expressing <i>trt1</i>^<i>+</i> and <i>tk</i>^<i>+</i>. The plasmid was retained on EMM plates supplemented with leucine and uracil (EMM+LU). (B) <i>trt1Δ pic1-T269</i> double mutants lost telomeric DNA. The loss of telomeric DNA in <i>trt1Δ pic1-T269</i> double mutant survivors was analyzed by Southern hybridization at 25°C. (C) NotI-digested chromosomal DNA from <i>pic1-T269</i>, <i>trt1Δ</i> and <i>trt1Δ pic1-T269</i> cells were analyzed by PFGE at 25°C. (D) Lack of function of Pic1 results in loss of the viability of <i>trt1Δ</i> with circular chromosome. <i>trt1Δ pic1-T269</i> double mutant cells having circular chromosomes were streaked on YEA plates at 33°C to examine the ability of the cells to grow. <i>trt1Δ</i> with circular chromosomes and <i>pic1-T269</i> were used as controls.