Gene expression of yeast under fluctuating environmental conditions

Regulating gene expression is crucial for the survival of yeast under fluctuating environmental conditions. Various regulating proteins and pathways are found to play important roles in responding to the environmental change at different levels. By utilizing two newly developed techniques: RNA sequencing and ribosome profiling, we are able to measure mRNA density and ribosome position of specific genes. Dom34, which has similar structure with eRF1, is known to dissemble stalled ribosome in mRNA, especially ribosomes arrested in the 3’UTR. In this thesis, we are focusing on how Dom34, regulate the presence of ribosomes in 3’UTR under different conditions. We verify potential Dom34 target genes and shows that Dom34 is partially inactivated under glucose starvation. Besides, we find no significant relation between translation recovery speed and ribosome distribution in 3’UTR. Though most starved genes will quickly return to their normal expression level after glucose re-addition, certain genes whose expression will be up-regulated under glucose deprivation remain in high level