a novel type of colony formation in marine planktonic diatoms revealed by atomic force microscopy集落形成的新型海洋浮游硅藻揭示了原子力显微镜.pdfVIP

A Novel Type of Colony Formation in Marine Planktonic Diatoms Revealed by Atomic Force Microscopy ˇ 1 ´2 ´2 ˇ ´2 3 ˇ ´ 1 Suncica Bosak *, Galja Pletikapic , Amela Hozic , Vesna Svetlicic , Diana Sarno , Damir Vilicic – ˇ ´ 1 Divison of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia, 2 Division for Marine and Environmental Research, Ruder Boskovic Institute, Zagreb, Croatia, 3 Stazione Zoologica Anton Dohrn, Naples, Italy Abstract Diatoms have evolved a variety of colonial life forms in which cells are connected by organic threads, mucilage pads or silicate structures. In this study, we provide the first description of a novel strategy of colony formation among marine planktonic diatoms. Bacteriastrum jadranum forms loose but regular chains with distinct heterovalvate terminal cells. The colonial cells and their siliceous projections, the setae, are not in direct contact; instead, they are enclosed within the optically transparent organic matrix. This cell jacket structure was detected by staining procedure with Alcian Blue, which showed that the polysaccharides are predominant matrix constituents and revealed that the jacket reaches the span of the setae. The scanning electron microscopy (SEM) observations showed distinguishable fibrillar network firmly associated with cells. Using atomic force microscopy (AFM), we were able to visualise and characterise the cell