Search

SUMMARY In the green alga Hydrodictyon reticulatum zoospores are arranged in a regular fashion to form an intricate hexagonal network during the asexual reproductive cycle. A monoclonal antibody which was raised against a homogenate of zoospores recognized a single polypeptide in zoospores with a molecular mass of 31 kDa. The antigenic polypeptide, which was designated Amy1, was localized within the cytoplasm of zoospores. The accumulation of Amy1 occurred concomitantly with the transition from multinuclear vegetative cells to mononuclear zoospores, and the degradation of Amy1 occurred concomitantly with the further development of zoospores. Amy1 was constantly expressed during the period of mononuclear zoospores. Thus, we conclude that Amy1 is a zoospore-specific polypeptide. Using the anti-Amy1 monoclonal antibody, we could easily distinguish between mononuclear zoospores and multinuclear vegetative net-cells. This provides an important tool for analysing the molecular mechanisms involved in the hexagonal net formation by zoospores. [ABSTRACT FROM AUTHOR]

SUMMARY In the green alga Hydrodictyon reticulatum (L.) Lagerheim (Chlorococcales, Chlorophyceae), zoospores are arranged in a regular fashion to form an intricate hexagonal network during the asexual reproductive cycle. Polypeptides that bind concanavalin A (Con A) in zoospores increased in amount during net formation and decreased after the completion of the adhesion between zoospores. Fluorescein isothiocyanate-Con A-binding sites corresponded to the contact sites of zoospores immediately after cessation of the movement. Treatment with 25 μg mL–1 Con A inhibited adhesion of isolated immotile zoospores obtained from parental cells, and Con A-treated zoospores could not form hexagonal nets. Moreover, when isolated immotile zoospores were treated with Con A, the cessation of the zoospore movement was retarded in dose-dependent manner. These results suggest that the Con A-binding sites may participate in the adhesion of zoospores during hexagonal net formation. [ABSTRACT FROM AUTHOR]