Figure 3.

Distribution of alternative mRNA isoforms in ranked polyribosome complexes. (Upper panel) Absorbance profile (A₂₆₀) of cytosolic extracts across 15%–45% sucrose gradient. Purified polyribosome fractions are indicated by P2 to ≥P9 corresponding to two ribosomes (P2) up to nine or more (≥P9). (Lower panels) Alternative splicing of KARS, HNRNPR, DGUOK, and DDX50 in different polyribosomal peak fractions assayed by RT-PCR and agarose gel electrophoresis. The constitutively spliced ACTB transcript is present at the bottom.