Chitin-based scaffolds in marine keratose demosponges: Morphology and structure, origin and role

• Applicant: Professor Dr. Hermann Ehrlich
• Subject Area: Systematics and Morphology (Zoology)
• Term: from 2011 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 194710577

Sponges are probably the earliest branching animals and their fossil record dates back to the Pre-cambrian. Over a long time, chitin was not recognized as an integral part of certain sponge skeletons. First observations of chitin-based scaffolds in Verongida sponge skeletons were reported recently by our group. The origin of this chitin is, however, not entirely clear since the presence of chitin synthase genes in the genome of the corresponding sponges has not yet been studied. The goal of the present paper is the systematic investigation of representative keratose sponge species from the orders Verongida, Dictyoceratida, and Dendroceratida with respect to the presence of chitinous scaffolds in their skeletons. These scaffolds will be characterized by various bioanalytical and physicochemical techniques in order to determine their morphology, composition, and structure. In particular, the embedded protein components (“cross linkers”) will be studied with respect to their structure. Furthermore, the chitin biosynthesis apparatus in these sponges will be studied within the present project. The suggested project will thus contribute to the understanding of the evolutionary origin of chitin synthases in the Metazoa. The comprehensive study of the species-specific morphology and structure of the chitin-based scaffolds will also be important for practical applications because the processing of chitin into synthetic sponge-like materials of comparable structure and morphology is rather complicated.

• DFG Programme: Research Grants