Studying translational control in non-model stressed organisms by polysomal profiling

In stressed organisms, strategic proteins are selectively translated even if the global process of protein synthesis is compromised. The determination of protein concentrations in tissues of non-model organisms (thus with limited genomic information) is challenging due to the absence of specific antibodies. Moreover, estimating protein levels quantifying transcriptional responses may be misleading, because translational control mechanisms uncouple protein and mRNAs abundances. Translational control is increasingly recognized as a hub where regulation of gene expression converges to shape proteomes, but it is almost completely overlooked in molecular ecology studies. An interesting approach to study translation and its control mechanisms is the analysis of variations of gene-specific translational efficiencies by quantifying mRNAs associated to ribosomes. In this paper, we propose a robust and streamlined pipeline for purifying ribosome-associated mRNAs and calculating global and gene-specific translation efficiencies from non-model insect's species. This method might found applications in molecular ecology to study responses to environmental stressors in non-model organisms.