Progenotes

Abstract

The progenote is a hypothetical candidate for the last universal cellular ancestor. There are two major conjectures associated with this entity: (1) the progenote's genome is based on RNA rather than DNA and (2) the replication, transcription and translation of this RNA organism had a much higher error rate than the ensuing DNA‚Äźbased cells.

Keywords: eukaryotes; prokaryotes; archaebacteria; eubacteria; endosymbiosis

Figure 1.

The three kingdoms: archaebacteria, eubacteria and urkaryotes emerge simultaneously from the universal ancestor, the progenote. (Adapted from Woese, Scientific American, 1981.)

Figure 2.

The tree based on ribosomal RNA has been rooted by using the elongation genes EF‐Tu and EF‐G. The tree shows the early branching of the eubacteria from the progenote and the later branching of the archaebacteria and the eukaryotes. (Adapted from Woese, ).

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References

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Further Reading

Hartman H (1992) The eukaryotic cell and the RNA‐protein world. In: Tran Thanh Van J, Tran Thanh Van K, Mounolou JC, Schneider J and Mckay C (eds) Frontiers of Life. Paris: Editions Frontières.

Hartman H (1992) The eukaryotic cell: evolution and development. In: Hartman H and Matsuno K (eds) The Origin and Evolution of the Cell. New Jersey: World Scientific Press.

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How to Cite close
Hartman, Hyman(Mar 2002) Progenotes. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1038/npg.els.0000463]