Abstract
Endosymbiotic origin of chloroplasts is believed as the most probable hypothesis. Many genes of endosymbiont origin must have been transferred to the initial photosynthetic eukaryote. We developed a software called 'Gclust' that clusters all protein sequences (about 110 thousand) of 17 representative organisms, such as eight cyanobacteria, three photosynthetic bacteria, two non-photosynthetic bacteria, two non-photosynthetic eukaryotes, as well as Arabidopsis and Cyanidioschyzon. Based on these results, the clusters that are shared by the eight cyanobacteria, plant and alga were extracted. We are trying to identify uncharacterized genes within these clusters. The 44 genes of Synechocystis are being disrupted. The 57 Arabidopsis genes are being characterized by analysis of tag lines, demonstration of chloroplast targeting and light-dependent expression.
