Fig 3.

Example electropherograms showing the detection and positioning of 15-nt insertions in the fragment covering nt 6546 to 6931 (ORF2) during selection in tissue culture. Peak size is depicted on the x axis, and fluorescence intensity is indicated on the y axis. The similar insertion profiles of the cDNA library and the RNA input suggest that diversity was not lost during in vitro transcription. Comparison of sequential passages reveals selection occurring within the insertion mutant populations. Insertions within the solid box were maintained, whereas the dashed box highlights a group of insertions that were rapidly lost. Peaks under 65 nt correspond to primer noise and were excluded from the analysis.