Figure 5

net1^tab2-1 cells display strong chromosomal segregation defect. A URA3-marked tester mini-chromosome carrying the SUP11 suppressor transfer RNA gene [34] was introduced into the indicated genetic background also harboring an ade2 mutation. Cells that retained the mini-chromosome would form white colonies due to suppression of ade2 by SUP11; the loss of this chromosome resulted in a red sector or sectors. When the loss event occurred at a very high frequency, a red colony could form. Cells were pre-grown in the uracil-lacking SD agar medium, and plated on YPD plates at room temperature. (A) After the initial signs of colony coloration appeared, the plates were kept at 4°C to enhance color development. White arrowheads indicate three sectoring events in a net1^tab2-1(net1-1) colony. (B) Percentages of colonies that were red or had red sectors were calculated.