Translational efficiency of a given messenger RNA can be inferred from the number of ribosomes simultaneously associated with it, since a more heavily translated mRNA carries more ribosomes (forming a polysome) and therefore behaves as a larger, denser ribonucleoprotein complex; sucrose density-gradient centrifugation separates mRNAs by this ribosome load, and combining fractionation with transcript-specific detection (e.g., RT-PCR) reveals where a given mRNA sediments and thus how efficiently it is translated. This belongs to the domain of molecular biology, specifically post-transcriptional/translational regulation of gene expression in eukaryotic cells, and relates to the broader discipline by providing a biophysical readout (sedimentation behavior) for a regulatory step — translation — that determines protein output independently of transcript abundance.
Translational efficiency of a given messenger RNA can be inferred from the number of ribosomes simultaneously associated with it, since a more heavily translated mRNA carries more ribosomes (forming …