首页 | 本学科首页   官方微博 | 高级检索  
   检索      


Larval development in <Emphasis Type="Italic">Guancha arnesenae</Emphasis> (Porifera,Calcispongiae, Calcinea)
Authors:Alexander V Ereskovsky  Philippe Willenz
Institution:(1) Centre d’Océanologie de Marseille, Station marine d’Endoume, Aix-Marseille Université, CNRS UMR 6540-DIMAR, rue de la Batterie des Lions, 13007 Marseille, France;(2) Department of Embryology, Faculty of Biology and Soils, Saint-Petersburg State University, Universitetskaja nab. 7/9, St. Petersburg, 199034, Russia;(3) Department of Invertebrates, Royal Belgian Institute of Natural Sciences, 29 rue Vautier, 1000 Brussels, Belgium
Abstract:Larval development and follicle structure of a representative of the Calcinea (Calcispongiae) Guancha arnesenae from the White Sea have been studied for the first time at the ultrastructural level. The follicle in G. arnesenae has an unusual structure: it consists of trapezoid cells rich in phagosomes and a surrounding dense collagen layer. Follicular cells differentiate from choanocytes. Cleavage results in formation of a hollow, equal, non-polarized coeloblastula. Larval morphogenesis occurs by means of direct hollow blastula formation without any individual cell or cell layer movements. The coeloblastula (calciblastula) larva of G. arnesenae is completely ciliated. The larva also contains rare non-ciliated cells: vacuolar cells, bottle-shaped cells and free cells in a central cavity. The basal ciliary apparatus of larval cells includes the basal body, an accessory centriole oriented perpendicularly to it, the basal foot, and two cross-striated rootlets. A bundle of microtubules emerges from the side of the basal body, opposite to the basal foot, running parallel to the outer surface. All bundles of cells are parallel to each other and oriented towards the posterior larval pole, forming a transverse cytoskeletal system. Specialized intercellular junctions in the apical regions of all ciliated cells are revealed for the first time in a Calcispongiae larva. The central larval cavity contains symbiotic bacteria, which are included inside the embryo at the blastula stage.
Keywords:Calcinea  Embryonic development  Larva  Coeloblastula  Phylogeny
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号