The cytoplasmic structure hypothesis for ribosome assembly, vertical inheritance, and phylogeny.
Fundamental questions in evolution concern deep divisions in the living world and vertical versus horizontal information transfer. Two contrasting views are: (i) three superkingdoms Archaea, Eubacteria, and Eukarya based on vertical inheritance of genes encoding ribosomes; versus (ii) a prokaryotic/eukaryotic dichotomy with unconstrained horizontal gene transfer (HGT) among prokaryotes. Vertical inheritance implies continuity of cytoplasmic and structural information whereas HGT transfers only DNA. By hypothesis, HGT of the translation machinery is constrained by interaction between new ribosomal gene products and vertically inherited cytoplasmic structure made largely of preexisting ribosomes. Ribosomes differentially enhance the assembly of new ribosomes made from closely related genes and inhibit the assembly of products from more distal genes. This hypothesis suggests experiments for synthetic biology: the ability of synthetic genomes to "boot," i.e., establish hereditary continuity, will be constrained by the phylogenetic closeness of the cell "body" into which genomes are placed.
Thaler
David S
DS
Raymond and Beverly Sackler Laboratory of Molecular Genetics and Informatics, Rockefeller University, 1230 York Avenue, New York, NY 10065, USA. thalerd@rockefeller.edu
D000818:Animals; D022083:Cytoplasmic Structures / Q000235:genetics*; D022761:Gene Transfer, Horizontal; D040582:Inheritance Patterns / Q000235:genetics*; D008957:Models, Genetic; D010802:Phylogeny; D012270:Ribosomes / Q000235:genetics*