What is the shortest known DNA?
Ostreococcus tauri is a marine photosynthetic picoeukaryote presenting a minimal cellular organization with one nucleus, one chloroplast, and one mitochondrion. It has the smallest genome actually described among free-living autotrophic eukaryotic cells and we showed by pulsed field gel electrophoresis (PFGE) that it is divided between 18 bands ranging from 1.2 to 0.15 Mb giving a total size of 11.5 Mb. From the very small size of its genome, it can be expected that many redundancies in the O. tauri genome have been eliminated, and its study may thus offer important clues regarding the minimum organization necessary for many cellular and/or molecular processes of a photosynthetic eukaryote. The O. tauri genome is simpler and more compact than plant genomes. It is one-tenth the size of the Arabidopsis genome, the smallest known plant genome, and has about 8,000 genes, just one-third the number found in Arabidopsis. Where plants have been observed to have complex gene families, O. tauri
