Trididemnum miniatum is a colonial ascidian harboring the photosymbiotic prokaryote Prochloron sp. These bacterial cells are located in the tunic of the host animal. The present study revealed, by ultrastructural analysis, that the Prochloron cells were exclusively distributed and proliferated in the tunic. They were shown to be embedded in the tunic matrix and to have no direct contact with ascidian cells. Some tunic cells of the ascidians, however, did phagocytize and digest the symbiont. Round cell masses were sometimes found in the tunic and appeared to consist of disintegrating cyanobacterial cells. The thoracic epidermis of ascidian zooids was often digitated, and the epidermal cells extended microvilli into the tunic. Since there were no Prochloron cells in the alimentary tract of the ascidian zooids, the photosymbionts would not be considered part of the typical diet of the host ascidians. Thin layer chromatography showed that the symbionts possessed both chlorophyll a and b, while a 16S rRNA gene phylogeny supported the identification of the photosymbiont of T. miniatum as Prochloron sp.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.