Karcz Jagna, Woznica Andrzej, Binkowski Marcin, Klonowska-Olejnik Malgorzata, Bernas Tytus, Karczewski Jerzy, Migula Pawel
Laboratory of Scanning Electron Microscopy, Faculty of Biology and Environmental Protection, University of Silesia, Katowice, Poland.
Folia Histochem Cytobiol. 2015;53(1):88-95. doi: 10.5603/FHC.a2015.0002. Epub 2015 Feb 13.
Freshwater sponges are common animals of most aquatic ecosystems. They feed by filtering small particles from the water, and so are thought to be sensitive indicators of pollution. Sponges are strongly associated with the abiotic environment and are therefore used as bioindicators for monitoring of water quality in water habitats. Among the freshwater sponges, Spongilla lacustris is one of the classic models used to study evolution, gene regulation, development, physiology and structural biology in animal water systems. It is also important in diagnostic of aquatic environments. The aim of this study was to characterize and visualize three-dimensional architecture of sponge body and measure skeleton elements of S. lacustris from Goczalkowice reservoir for identification purposes.
The scanning electron microscopy with an energy dispersive X-ray microanalysis (SEM- -EDS) and X-ray micro computed tomography (micro-CT) were used to provide non-invasive visualization of the three-dimensional architecture of Spongilla lacustris body.
We showed that sponge skeleton was not homogeneous in composition and comprised several forms of skeleton organization. Ectosomal skeleton occurred as spicular brushes at apices of primary fibres with cementing spongin material. Choanosomal skeletal architecture was alveolate with pauci- to multispicular primary fibres connected by paucispicular transverse fibres, made by megascleres embedded in a scanty spongin matrix both in the choanosome and at the sponge surface. In contrast, microscleres were irregularly scattered in choanosome and skeletal surface. Furthermore, SEM-EDS studies showed that the distribution of silica in megascleres and microscleres was observed along the spicules and sponge surface areas.
In conclusion, we showed that the combination of SEM-EDS and micro-CT microscopy techniques allowed obtaining a complete picture of the sponge spatial architecture.
淡水海绵是大多数水生生态系统中的常见动物。它们通过过滤水中的小颗粒来进食，因此被认为是污染的敏感指标。海绵与非生物环境密切相关，因此被用作监测水生生境水质的生物指标。在淡水海绵中，湖海绵是研究动物水系统中的进化、基因调控、发育、生理学和结构生物学的经典模型之一。它在水生环境诊断中也很重要。本研究的目的是对海绵体的三维结构进行表征和可视化，并测量来自戈恰尔科维采水库的湖海绵的骨骼元素以用于识别目的。
使用带有能量色散X射线微分析的扫描电子显微镜（SEM-EDS）和X射线微计算机断层扫描（micro-CT）对湖海绵体的三维结构进行非侵入性可视化。
我们发现海绵骨骼的组成并不均匀，包括几种骨骼组织形式。体表骨骼以初级纤维顶端的针状刷形式出现，并伴有粘结海绵质材料。领细胞层骨骼结构呈蜂窝状，有少量到多针状的初级纤维，由少量针状横向纤维连接，这些横向纤维由嵌入领细胞层和海绵表面稀疏海绵质基质中的大骨针构成。相比之下，小骨针不规则地散布在领细胞层和骨骼表面。此外，SEM-EDS研究表明，在大骨针和小骨针中以及海绵表面区域都观察到了硅的分布。
总之，我们表明SEM-EDS和micro-CT显微镜技术的结合能够全面了解海绵的空间结构。
