Cytological Observations of the Large Symbiotic Foraminifer Amphisorus kudakajimensis Using Calcein Acetoxymethyl Ester.
Large benthic foraminifera are unicellular calcifying reef organisms that can form symbiotic relationships with a range of different microalgae. However, the cellular functions, such as symbiosis and calcification, and other aspects of cellular physiology in large benthic foraminifera are not fully understood. Amphisorus kudakajimensis was used as a model to determine the detailed cellular characteristics of large benthic foraminifera. We used calcein acetoxymethyl ester (calcein AM) as a fluorescent indicator for live confocal imaging. We demonstrated that calcein AM is a useful fluorescent indicator to stain the fine network of reticulopodia and the cytoplasm in living A. kudakajimensis. We showed that at least two types of reticulopodia exist in A. kudakajimensis: the straight bundle of reticulopodia that spreads from the aperture and the fine reticulopodia along the surface of the aperture and chamber walls. The cytoplasm in outer chambers was highly branched and contained a few dinoflagellates. In contrast, the inner chamberlets contained condensed cytoplasm and many dinoflagellates, suggesting that the cytoplasm of A. kudakajimensis performs different functions based on its location within the large test. Our confocal detailed image analysis provides real-time cellular morphology and cell physiology of living foraminifera.
Marine and Environmental Sciences Course, Graduate School of Engineering and Science, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
Yoshikazu
Y
Ohno
Department of Physics and Earth Sciences, Faculty of Science and Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.
Kazuhiko
K
Fujita
Department of Marine Biodiversity Research (B-DIVE), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka 237-0061, Japan.
Takashi
T
Toyofuku
Department of Chemistry, Biology and Marine Science, Faculty of Science and Tropical Biosphere Research Center, University of the Ryukyus, Senbaru 1, Nishihara, Okinawa 903-0213, Japan.|Japan Science and Technology Agency (JST)/ Japan International Cooperation Agency (JICA) SATREPS, Tokyo Headquarters, 8th Floor, K's Gobancho 7, Gobancho, Chiyoda-ku, Tokyo 102-0076, Japan.
Takashi
T
Nakamaura
D003593:Cytoplasm / Q000378:metabolism; D005452:Fluoresceins / Q000378:metabolism*; D056908:Foraminifera / Q000166:cytology* / Q000378:metabolism* / Q000502:physiology; D061848:Optical Imaging; D013194:Staining and Labeling; D013559:Symbiosis
D005452:Fluoresceins; C085925:calcein AM