Fig. 4.

Galactose-evolved mutations show variation in fitness effect and carbon source dependence. Average fitness effects of the reconstructed mutations in snt1 (n = 4), sec23 (n = 6), and ira1 (n = 4) in both zygosities; A heterozygous and B homozygous mutations. Fitness effect were compared with wild-type version (n = 6), hsl1 mutation (n = 4) from glucose, haploid evolution (Fisher et al. 2018), and ace2 mutation (n = 4) from glucose, diploid-evolution (Marad et al. 2018). We were not able to generate hsl1 homozygous mutation. The sec23-R592I has a significant fitness gain in galactose compare to glucose. Asterisk (****) indicate p < 10–8, (***) p < 10–5, (**) p < 10–4, (*) p < 10–3, and NS: not significant; one-way ANOVA, tukey's HSD test. Error bars are the s.e.m