Chromerids are a group of alveolates, found in corals, that show peculiar morphological and genomic features. These organisms are evolutionary placed in-between symbiotic dinoflagellates and parasitic apicomplexans. There are two known species of chromerids: Chromera velia and Vitrella brassicaformis. Here, the biochemical composition of the C. velia cell wall was analyzed. Several polysaccharides adorn this structure, with glucose being the most abundant monosaccharide (approx. 80%) and predominantly 4-linked (approx. 60%), suggesting that the chromerids cell wall is mostly cellulosic. The presence of cellulose was cytochemically confirmed with calcofluor white staining of the algal cell. The remaining wall polysaccharides, assuming structures are similar to those of higher plants, are indicative of a mixture of galactans, xyloglucans, heteroxylans, and heteromannans. The present work provides, for the first time, insights into the outermost layers of the photosynthetic alveolate C. velia.

CSIRO Agriculture and Food Canberra 2601 Australian Capital Territory Australia

Department of Animal Plant and Soil Sciences La Trobe Institute for Agriculture and Food La Trobe University AgriBio Building Bundoora Victoria Australia

Faculty of Science University of South Bohemia 37005 České Budějovice Czech Republic

Institute of Parasitology Biology Centre Czech Academy of Sciences 370 05 České Budějovice Czech Republic

School of Biosciences The University of Melbourne Parkville 3010 Victoria Australia

State Key Laboratory of Biocontrol Center for Parasitic Organisms School of Life Sciences Sun Yat Sen University Guangzhou 510275 China

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Cavalier‐Smith, T. 2018. Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cyto‐skeletal and periplastid evolution, and ancient divergences. Protoplasma 255:297–357. PubMed PMC

Flegontov, P. , Michálek, J. , Janouškovec, J. , Lai, D. H. , Jirků, M. , Hajdušková, E. , Tomčala, A. et al. 2015. Divergent mitochondrial respiratory chains in phototrophic relatives of apicomplexan parasites. Mol. Biol. Evol. 32:1115–31. PubMed

Fritz, L. & Triemer, R. E. 1985. A rapid simple technique utilizing calcofluor white M2R for the visualization of dinoflagellate thecal plates. J. Phycol. 21:662–4.

Gould, S. B. , Tham, W. H. , Cowman, A. F. , McFadden, G. I. & Waller, R. F. 2008. Alveolins, a new family of cortical proteins that define the protist infrakingdom Alveolata. Mol. Biol. Evol. 25:1219–30. PubMed

Janouškovec, J. , Horák, A. , Oborník, M. , Lukeš, J. & Keeling, P. J. 2010. A common red algal origin of the apicomplexan, dinoflagellate, and heterokont plastids. Proc. Natl. Acad. Sci. USA 107:10949–54. PubMed PMC

Mathur, V. , Del Campo, J. , Kolisko, M. & Keeling, P. J. 2018. Global diversity and distribution of close relatives of apicomplexan parasites. Environ. Microbiol. 20:2824–33. PubMed

McFadden, G. I. & Waller, R. F. 1997. Plastids in parasites of humans. BioEssays 19:1033–40. PubMed

Moore, R. B. , Oborník, M. , Janouškovec, J. , Chrudimský, T. , Vancová, M. , Green, D. H. , Wright, S. W. et al. 2008. A photosynthetic alveolate closely related to apicomplexan parasites. Nature 451:959–63. PubMed

Oborník, M. , Kručinská, J. & Esson, H. 2016. Life cycles of chromerids resemble those of colpodellids and apicomplexan parasites. Perspect. Phycol. 3:21–7.

Oborník, M. & Lukeš, J. 2013. Cell biology of chromerids: autotrophic relatives to apicomplexan parasites. Int. Rev. Cell Mol. Biol. 306:333–69. PubMed

Oborník, M. , Modrý, D. , Lukeš, M. , Černotíková‐Stříbrná, E. , Cihlář, J. , Tesařová, M. , Kotabová, E. , Vancová, M. , Prášil, O. & Lukeš, J. 2012. Morphology, ultrastructure and life cycle of Vitrella brassicaformis n. sp., n. gen., a novel chromerid from the Great Barrier Reef. Protist 163:306–23. PubMed

Oborník, M. , Vancová, M. , Lai, D. H. , Janouškovec, J. , Keeling, P. J. & Lukeš, J. 2011. Morphology and ultrastructure of multiple life cycle stages of the photosynthetic relative of apicomplexa, Chromera velia . Protist 162:115–30. PubMed

Okamoto, N. & McFadden, G. I. 2008. The mother of all parasites. Future Microbiol. 3:391–5.

Pettolino, F. A. , Walsh, C. , Fincher, G. B. & Bacic, A. 2012. Determining the polysaccharide composition of plant cell walls. Nat. Protoc. 7:1590–607. PubMed

Popper, Z. A. , Michel, G. , Hervé, C. , Domozych, D. S. , Willats, W. G. , Tuohy, M. G. , Kloareg, B. & Stengel, D. B. 2011. Evolution and diversity of plant cell walls: from algae to flowering plants. Annu. Rev. Plant Biol. 62:567–90. PubMed

Synytsya, A. , Čopíková, J. , Kim, W. J. & Park, Y. I. 2015. Cell wall polysaccharides of marine algae. In Kim, S. K. [Ed.] Springer Handbook of Marine Biotechnology. New York, NY: Springer, pp. 543–90.

Weatherby, K. & Carter, D. 2013. Chromera velia: the missing link in the evolution of parasitism. Adv. Appl. Microbiol. 85:119–44. PubMed

Woo, Y. H. , Ansari, H. , Otto, T. D. , Klinger, C. M. , Kolisko, M. , Michálek, J. , Saxena, A. et al. 2015. Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites. eLife 4:e06974. PubMed PMC