caa a22 4500 475768310 CHVBK 20180406123612.0 cr unu---uuuuu 170329e20000401xx s 000 0 eng 10.1007/s004270050313 doi (NATIONALLICENCE)springer-10.1007/s004270050313 All meiotic chromosomes and both centrosomes at spindle pole in the zygotes discarded as two polar bodies in clam Corbicula leana [Elektronische Daten] unusual polar body formation observed by antitubulin immunofluorescence [A. Komaru, Kennichi Ookubo, Masato Kiyomoto] Abstract : To understand the unusual polar body formation in the androgenetic clam, Corbicula leana, whole-mount eggs stained with monoclonal antibodies against α-tubulin, γ-tubulin, and 4'-6'-diamidino-2-phenylindole were examined. The meiotic spindle was located at the peripheral region of the egg at metaphase I, and its axis was parallel to the egg surface. After segregation of chromosomes at anaphase I, cytoplasmic bulges formed at both meiotic spindle pole sites. Centrosomes were located at the apical portion of the each bulge. From the apical portion of the bulge a bundle of astral microtubules radiated toward the bulge base in late anaphase resembling a half spindle. Maternal chromosomes and both centrosomes were all distributed in two ”first polar bodies” and were eventually discarded. After the polar body formation only one male pronucleus existed in the egg cytoplasm. The present study showed that the anaphase microtubules originating from a single aster can induce the polar body formation without overlapping of microtubules from the opposing aster. Springer-Verlag Berlin Heidelberg, 2000 Key words α-Tubulin nationallicence Centrosome nationallicence Polar body formation nationallicence Androgenesis nationallicence Komaru A. Faculty of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan, JP aut Ookubo Kennichi Faculty of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan, JP aut Kiyomoto Masato Tateyama Marine Laboratory, Ochanomizu University, Tateyama, Chiba 294-0301, Japan, JP aut https://doi.org/10.1007/s004270050313 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s004270050313 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Komaru A. Faculty of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan, JP aut NATIONALLICENCE 700 1- Ookubo Kennichi Faculty of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan, JP aut NATIONALLICENCE 700 1- Kiyomoto Masato Tateyama Marine Laboratory, Ochanomizu University, Tateyama, Chiba 294-0301, Japan, JP aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer