|Budget Amount *help
¥1,500,000 (Direct Cost : ¥1,500,000)
Fiscal Year 1991 : ¥300,000 (Direct Cost : ¥300,000)
Fiscal Year 1990 : ¥1,200,000 (Direct Cost : ¥1,200,000)
The problem on the evolution from prokaryote to eukaryote has been discussed from a long time between endosymbiotic theory and direct filiation theory. The present task could offered a material for this discussion from a such of the most primitivealgae. We surveyed microalgae occured in acid-hot springs such as Narugo, Goshokake spas in Tohoku district, and Niseko spa in Hokkaido in Japan, and those in Yellostone National Park, U. S. A. An Unicellular, eukaryotic, blue-green Prerhodophyta, Cyanidium caldarium is widely distributed in these hot-springs, and Galdieria sulphuraria is confined in Niseko spa and in hot springs in Yellowstone National Park. Cyanidioschyzon sp. YR-89, was newly isolated from acid-hot springs in Yellowstone National Park, using a micromanipulator. Typically the cell is clubshaped with a narrow gourd-like section, 1 x 3 mum in size, unlike Cyanidioschyzon merolae whose cell is club-shaped without a narrow section. The cell is surrounded by thin and labile membrane, and the cell shape is sometimes irregular. It has a nucleus and an ovoid chloroplast which has granular chloroplast nucleoid (DNA containing area), and unstacked thylakoids like Cyanidioschyzon melorae and Cyanidium caldarium. The probability is discussed, that those most primitive eukaryotic algae (two Cyanidioschyzon species) might be evolved by endosymbiotic process.