title: THE OOGONIA OF MACROALGA UNDARIA PINNATIFIDA ARE ALKALINE-PHOSPHATASE POSITIVE AND CONTAIN GERMINAL BODY-LIKE STRUCTURES(1).
abstract: It was observed that in the female gametophyte of Undaria pinnatifida (Harv.) Suringar (Phaeophyta, Laminariales) gametangial initials and maturing oogonia demonstrated different levels of alkaline-phosphatase activity (APA). The oogonia exhibited a higher level of APA than in its initials. Electron-dense granular ovoid structures ∼0.5-0.6 μm were present in the cytoplasm of oogonia. These inclusions were not membrane bound and do not appear to be associated with any particular organelles. The number of the inclusions was 1 to 2 in a single section of the cell. In essential details, the specific APA and subcellular germinal body-like structure of the developing female gamete in U. pinnatifida were very similar to those in metazoan oocytes.
authors.affiliation: A.V. Zhirmunsky Institute of Marine Biology FEB RAS, 17 Palchevskogo str., Vladivostok 690041, Russia.
authors.forename: Ya N
authors.initials: YN
authors.lastname: Alexandrova
authors.affiliation: A.V. Zhirmunsky Institute of Marine Biology FEB RAS, 17 Palchevskogo str., Vladivostok 690041, Russia.
authors.forename: A A
authors.initials: AA
authors.lastname: Reunov
keywords: Phaeophyta; Undaria; alkaline-phosphatase activity; germinal body-like structures; ultrastructure