Progressive transcriptomic shifts in evolved yeast strains following gene knockout.

Gene knockout disrupts cellular homeostasis, altering gene expression, and phenotypes. We investigated whether cells return to their pre-knockout transcriptomic state through adaptive evolution experiments on hap4Δ and ade1Δ yeast strains. Analysis revealed that genes with higher expression levels and more physical interaction partners in wild-type strains were more likely to be restored, suggesting that genes of significant functional importance have increased resilience to genetic perturbations. However, as the experiment progressed, most initially restored genes became unrestored. Over 60% of differentially expressed genes in knockout strains remained unrestored in evolved strains. Evolved strains exhibited distinct transcriptomic states, diverging from the original strain over time. Ribosome biogenesis components exhibited systematic sequential changes during the evolution. Our findings suggest the knockout strain transcriptomes struggle to return to the original state even after 28 days of culture. Instead, compensatory mechanisms lead to distinct suboptimal states, highlighting the complex transcriptomic dynamics following genetic perturbations.