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Organization of the coelomic system in Phoronis australis (Lophotrochozoa: Phoronida) and consideration of the coelom in the lophophoratesстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Автор: Temereva Elena
- Журнал: Journal of Zoology
- Том: 295
- Номер: 2
- Год издания: 2015
- Издательство: Cambridge University Press
- Местоположение издательства: United Kingdom
- DOI: 10.1111/jzo.12223
- Аннотация: The organization of the phoronid coelomic system has traditionally been regarded as similar to that of the deuterostomians, because both have three coelomic compartments: the proto-, meso-, and metacoel. Recent investigations, however, have revealed the presence of two coelomic compartments in specimens from the genus Phoronis and three in specimens from genus Phoronopsis. The current study attempted to determine which type of coelomic system organization is plesiomorphic for phoronids. The organization of the coelomic system of Phoronis australis, which is the largest species of Phoronis, was investigated by transmission electron microscopy and 3D reconstruction. P. australis has three coelomic compartments. The protocoel is the closed cavity, which is located at the base of the epistome, consists of two lateral branches and a central part, and has own epithelial lining that is formed by non-muscular epithelial and myoepithelial cells. According to these features, the protocoel must be regarded as a true coelom. The mesocoel base surrounds the esophagus and gives rise to channels that extend into each tentacle. The mesocoel lining consists of two cell types, non-muscular epithelial and myoepithelial cells, which alternate and interconnect via desmosomes. The metacoel is subdivided into four chambers by five mesenteries. In the anterior part of the body, the metacoel lining is formed by epithelial cells, which cover the surface of the longitudinal muscles. Coelomic organization was compared in phoronids, brachiopods, and bryozoans. Both phoronids and brachiopods exhibit two types of coelomic organization—bipartite and tripartite—while bryozoans have a coelomic organization that is completely different from that in phoronids and brachiopods. The tripartite coelom appears to be the plesiomorphy for the Brachiozoa. In phoronids, the coelomic lining can be organized as a primitive monociliate myoepithelium, as an advanced type with alternation of epithelial and myoepithelial cells, or as a specialized coelothelium.
- Добавил в систему: Темерева Елена Николаевна