Rapid tissue reduction and recovery in the sponge Aplysinella sp.
Rapid tissue reduction and recovery in the sponge Aplysinella sp.
复制标题
海绵海兔的组织快速减少和恢复。
DOI：
10.1007/s00227-008-1071-3
复制
发表时间：
2008
期刊：
影响因子：
2.4
通讯作者：
P. Schupp
中科院分区：
文献类型：
--
作者：
C. Thoms;U. Hentschel;Susan Schmitt;P. Schupp
我们观察到热带海绵Aplysinella sp.在其自然栖息地的非实验条件下，在转移到海水池后，以及在田间从深水移植到浅水后，组织明显减少，但可逆。组织减少导致形成小的“还原体”紧紧附着在海绵骨架上。虽然体积损失和增加都很大，但组织减少和再生往往非常迅速，在几小时内发生。显微镜分析显示，还原体的形态与先前描述的海绵原形相似，具有密集排列的原始细胞和被薄层上皮样细胞包围的球形细胞。变性梯度凝胶电泳（DGGE）显示，在实验室和田间实验中，海绵相关微生物群落在组织减少后以及在田间移植后环境条件的变化中发生了显著变化。一般来说，与这种海绵相关的微生物群落被证明比其他先前研究过的维龙科海绵更不稳定、更少丰富、更少多样化。然而，在Aplysinella sp.的DGGE图谱中一致存在一个单一的种型，该种型与以前在不同分类隶属关系和地理来源的其他海绵物种以及海绵幼虫中发现的γ-变形菌序列聚集在一起。在组织还原后，白杨菌总次生代谢物含量（每干重）无明显变化；然而，完整组织和还原组织的比较分析表明，两种次要化合物的浓度发生了变化。除了具有生态学意义外，Aplysinella sp.的组织减少现象为海绵/微生物共生研究提供了一个实验操作系统。此外，它可能被证明是一种有用的模型系统，用于研究体内基本后生动物性状的分子机制，补充了目前在此背景下使用的体外海绵原始系统。
We observed a pronounced, yet reversible tissue reduction in the tropical sponge Aplysinella sp. under non-experimental conditions in its natural habitat, after transfer into seawater tanks, as well as after transplantation from deep to shallow water in the field. Tissue reduction resulted in the formation of small “reduction bodies” tightly attached to the sponge skeleton. Although volume loss and gain were substantial, both tissue reduction and regeneration were often remarkably rapid, occurring within few hours. Microscopic analysis of the reduction bodies revealed morphological similarities to previously described sponge primmorphs, with densely packed archaeocytes and spherulous cells enclosed by a thin layer of epithelial-like cells. Denaturing gradient gel electrophoresis (DGGE) revealed pronounced changes in the sponge-associated microbial community upon tissue reduction during laboratory and field experiments and following changes in ambient conditions after transplantation in the field. Generally, the microbial community associated with this sponge proved less stable, less abundant, and less diverse than those of other, previously investigated Verongid sponges. However, one single phylotype was consistently present in DGGE profiles of Aplysinella sp. This phylotype clustered with γ-proteobacterial sequences found previously in other sponge species of different taxonomic affiliations and geographic provenances, as well as in sponge larvae. No apparent changes in the total secondary metabolite content (per dry weight) occurred in Aplysinella sp. upon tissue reduction; however, comparative analysis of intact and reduced tissue suggested changes in the concentrations of two minor compounds. Besides being ecologically interesting, the tissue reduction phenomenon in Aplysinella sp. provides an experimentally manipulable system for studies on sponge/microbe symbioses. Moreover, it may prove useful as a model system to investigate molecular mechanisms of basic Metazoan traits in vivo, complementing the in vitro sponge primmorph system currently used in this context.