FIG 6.

Dominant growth of DA4 at lower temperatures. KU216 and DA4 cells were precultured separately at 85°C. The two cultures were then mixed at different KU216/DA4 ratios (1:1, 10:1, 10²:1, and 10⁴:1) and cultured at 50°C for 2 days. The cultures were then added to fresh growth medium and cultured for another 2 days. The log-phase cultures were spread onto solid medium and cultured overnight at 85°C. Over 100 colonies for each KU216/DA4 ratio were randomly picked and genotyped by PCR, using primer pairs SNP-E530-Fw/SNP-E530-Rv and SNP-E530-Fw/SNP-E530G-Rv. (A) Genotypes of colonies confirmed by PCR and sequencing. The results for 10 representative colonies for each KU216/DA4 ratio are shown. The results were confirmed by sequencing (shown at the bottom of gels). K, KU216 genotype; D, DA4 genotype. (B) Proportions of DA4 and KU216 cells in cocultures at each KU216/DA4 ratio after culture at 50°C. DA4 and KU216 are indicated by black and white bars, respectively.