Transcriptome analysis of cell wall biomineralization in the large diatom Coscinodiscus
Authors
Felicity Ashcroft [1]
Per Winge [1]
Fabian Hitz [1]
Pedro Fernandes [2]
Vera Cardoso [3]
Jose Prada-Rodrigo [4]
Johannes W. Goessling [3]
Martin Lopez-Garcia [4]
Tore Brembu (presenting author) [1]
Keywords
Diatom; frustule; photonic crystal; transcriptomics
Abstract
A defining feature of diatoms are their silica-based cell wall (frustule), with highly ornate, species-specific structures and pore patterning. While considerable research has focused on the formation of the larger, more elaborate silica structures that make up the valves, the smaller and more uniform girdle bands have received less attention. Recently, the girdle bands of species belonging to the Coscinodiscus genus were identified as natural photonic crystals due to their highly ordered arrangement of nanopores. Unravelling the genetic basis of pore pattern formation in these structures could support the development of more sustainable photonic technologies. We wanted to find candidate genes determining photonic crystal properties in C. granii and C. wailesii, which respectively have square and hexagonal pore lattices. To this end, we combined fluorescence microscopy to monitor girdle band appearance in synchronized cultures with time-resolved RNA-seq transcriptomics. By integrating these experimental approaches, we were able to identify silica-responsive genes specifically upregulated during girdle band formation. We are also in the process of establishing genetic transformation and gene editing in Coscinodiscus. We aim to use these results to modify the photonic crystal properties of Coscinodiscus girdle bands through genetic manipulation.
Funding
NFR, Enabling natural photonics through genetic manipulation of diatoms/ENIGMA, granted to Tore Brembu