There's DNA in those organelles ractionation experiments in the early 1960s suggested that certain organelles may contain DNA (see Gibor and Granick, 1964, for review), but varying levels of nuclear contamination marred those results. Meanwhile, oddities in genetic transmission chipped away at the nucleus-only theory of genetic inheritance. But it took direct visualization to convince most skep...

Evolutionary relationships among complex, multicellular eukaryotes are generally interpreted within the framework of molecular sequence-based phylogenies that suggest green plants and animals are only distantly related on the eukaryotic tree. However, important anomalies have been reported in phylogenomic analyses, including several that relate specifically to green plant evolution. In addition...

Establishment of a successful symbiosis between rhizobia and legumes results from an elaborate molecular dialogue between both partners. Bacterial nodulation (Nod) factors are indispensable for initiating plant responses, whereas bacterial surface polysaccharides are important for infection progression and nodule development. The mutant ORS571-oac2 of Azorhizobium caulinodans, affected in its s...

Resolving the structure of the eukaryotic tree of life remains one of the most important and challenging tasks facing biologists. The notion of six eukaryotic 'supergroups' has recently gained some acceptance, and several papers in 2007 suggest that resolution of higher taxonomic levels is possible. However, in organisms that acquired photosynthesis via secondary (i.e. eukaryote-eukaryote) endo...

This paper reviews and extends ideas of eukaryotization by endosymbiosis. These ideas are put within an historical context of processes that may have led up to eukaryotization and those that seem to have resulted from this process. Our starting point for considering the emergence and development of life as an organized system of chemical reactions should in the first place be in accordance with...

New work in aphids shows that a nuclear-encoded protein resulting from a horizontal gene transfer is targeted to a bacterial symbiont, further blurring the distinction between organelle and symbiont.