An Electron Microscopic Study of Large Bacterial Polyribosomes

Ribosome Substructure in Intact Mouse Liver Cells

“…8) reveal that both large and small subunits are composed of 20-40 A electron opacities, which stand out above under-and over-focus background phase effects (6,19) . These opacities may correspond to the substructure observed by Nanninga (12) (20), observing a similar pattern in positively contrasted large bacterial polyribosomes, suggest that this pattern may arise from spurious stain exclusion or stain deposition . The reality of the electron image observed in this study must await further studies on the interaction of stain and biological material .…”

Spatially segregated transcription and translation in cells of the endomembrane-containing bacterium Gemmata obscuriglobus

“…Inhibition of translation by antibiotic treatment produced a change in EF-Tu distribution in G. obscuriglobus cells, confirming that EF-Tu participates in active translation. The punctate distribution of fluorescent signal for both S10 and EF-Tu may result from the majority of ribosomes occurring as polysomes (44)(45)(46)(47). However, variations in cytoplasmic mRNA density cannot be excluded.…”

Rough Thylakoids: Polysomes Attached to Chloroplast Membranes

“…The center-to-center distances within the plastidal polysome spirals, however, are nearly identical to the values reported by Slayter et al . (34) for a special sort of polysomes in E. coli (194-232 A) and noticeably greater than the values of about 130 A communicated for a helical type of polysome in Rhodopseudomonas palustris (38) . At higher magnification an electron-opaque strand, 10-15 A broad, can be occasionally encountered connecting the ribosomes into the spiral polysome, thus suggesting its interpretation as the messenger-strand (Figs .…”