Ribosome Heterogeneity in Plant and Animal Organisms. Its Relationship to Ribosomal Ambiguity and to Ribosome Evolution

Abstract The data presented and discussed in this report summarize evidence showing that ribosomes isolated from several eucaryotic (plant and animal) organisms exhibit ample variations of the composition of their protein moiety and that the degree of dissimilarity correlates with the degree of taxonomic kinship of the organisms from which the ribosomes were derived. They also provide evidence that (a) the 80-S ribosomes isolated from the cytoplasmic matrix of higher plants and yeast and the 70-S ribosomes derived from both chloroplasts and mitochondria are endowed with highly dissimilar protein complements, (b) the organellar (67-S) ribosomes derived from the chloroplasts of more or less d…