mRNAs present in the cell need to be translated to produce functional proteins. mRNA translation is a highly regulated process with multiple layers of control. Although translation initiation has been considered the rate-limiting step, and thus has been more intensively studied, recent evidence suggests that translation elongation is also highly regulated. Our lab has previously developed a method termed 5PSeq that takes advantage of the mRNA co-translational 5’-3’degradation to produce an in vivo ribosomal footprint. This approach, by sequencing the ends of 5’phosphorylated mRNA degradation intermediates, obtains a genome-wide drug-free measurement of ribosome dynamics. We will use this approach to investigate translation responses in yeast, bacteria and eukaryote samples.