| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1989: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000)
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| Research Abstract |
A further description of the green dinoflagellate, strain Y-100, with a chlorophyll a- and b- containing endosymbiont is given with special emphasis on the morphology of the host cell. The host dinoflagellate cell is unarmored and has a gymnodinioid overall appearance. The theca or amphiesma basically consists of the outer membrane and flattened thecal vesicles in which no thecal plates are developed. Unusual hand basket-shaped scales cover the entire cell surface together with a layer of mucillaginous material. These findings suggest that the organism is a new member of the Gymnodiniaceae (Gymnodiniales) ; We propoes the name Lepidodinium viride gen. et sp. nov. The ultrastructure of the host cell is basically typical of the dinoflagellates. However, the organism has 1) an usual cytoplasmic projection that may be a homologue of the peduncle, 2) a single membrane-bounded body containing membranous sheets, closely situated next to the endosymbiont, and 3) an electron opaque network-forming appendage surrounding the transverse flagellum. None of these features have been found in other dinoflagellates.
Major carotenoids of a endosymbiont in a green dionflagellate, Lepidodinium viride have been analyzed using high-performance liquid chromatography (HPLC). The endosymbiont contains the usual chlorophytes carotenoids, that are neoxanthin, violaxanthin, antheraxanthin and beta-carotene. In addition to thses carotenoids, the two unknown peaks were detected. One peak of the tow is situated at the identical retention time to that of lutein, however, the absorption spectra is diffrent from that of lutein obtained from spinach leaves. Another peak cannot be identified becaues it has quite low absorbance, but seems to be identical to that of zeaxanthin. Based on these results, it is speculated that a prasinophyte would seem to be likeliest candidate for a proqenitor of the endosymbiont.
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