['Turnip yellow mosaic virus (TYMV) is a small icosahedral plant virus with a capsid containing 180 subunits arranged with hexamer-pentamer clustering. Cross-linking studies have indicated extensive contacts between RNA and coat protein, suggesting that substantial parts of the RNA might be icosahedrally ordered.', 'Comparison of maps computed to a Fourier cut-off of 1.5 nm from electron micrographs of ice-embedded specimens of TYMV and of empty capsids produced by freeze-thawing reveals strong inner features around the threefold axes in the virus but not in the empty capsid. Internal features of subunit packing indicate that interhexamer contacts are closer than those between pentamers and hexamers and that pentamer density in the empty capsid is reduced relative to that in the virus.'] Does difference imaging reveal ordered regions of RNA in turnip yellow mosaic virus?