Author:
Gorman Lucy M.,Wilkinson Shaun P.,Kitchen Sheila A.,Oakley Clinton A.,Grossman Arthur R.,Weis Virginia M.,Davy Simon K.
Abstract
AbstractIn oligotrophic waters, cnidarian hosts rely on symbiosis with their photosynthetic dinoflagellate partners (family Symbiodiniaceae) to obtain the nutrients they need to grow, reproduce and survive. For this symbiosis to persist, the host must regulate the growth and proliferation of its symbionts. One of the proposed regulatory mechanisms is arrest of the symbiont cell cycle in the G1 phase, though the cellular mechanisms involved remain unknown. Cell-cycle progression in eukaryotes is controlled by the conserved family of cyclin-dependent kinases (CDKs) and their partner cyclins. We identified CDKs and cyclins in different Symbiodiniaceae species and examined their relationship to homologs in other eukaryotes. Cyclin proteins related to eumetazoan cell-cycle-related cyclins A, B, D, G/I and Y, and transcriptional cyclin L, were identified in the Symbiodiniaceae, alongside several alveolate-specific cyclin A/B proteins, and proteins related to protist P/U-type cyclins and apicomplexan cyclins. The largest expansion of Symbiodiniaceae cyclins was in the P/U-type cyclin groups. Proteins related to eumetazoan cell-cycle-related CDKs (CDK1) were identified as well as transcription-related CDKs. The largest expansion of CDK groups was, however, in alveolate-specific groups which comprised 11 distinct CDK groups (CDKA-J) with CDKB being the most widely distributed CDK protein. As a result of its phylogenetic position, conservation across Symbiodiniaceae species, and the presence of the canonical CDK motif, CDKB emerged as a likely candidate for a Saccharomyces cerevisiae Cdc28/Pho85-like homolog in Symbiodiniaceae. Similar to cyclins, two CDK-groups found in Symbiodiniaceae species were solely associated with apicomplexan taxa. A comparison of Breviolum minutum CDK and cyclin gene expression between free-living and symbiotic states showed that several alveolate-specific CDKs and two P/U-type cyclins exhibited altered expression in hospite, suggesting that symbiosis influences the cell cycle of symbionts on a molecular level. These results highlight the divergence of Symbiodiniaceae cell-cycle proteins across species. These results have important implications for host control of the symbiont cell cycle in novel cnidarian–dinoflagellate symbioses.
Publisher
Springer Science and Business Media LLC
Reference79 articles.
1. Davy, S. K., Allemand, D. & Weis, V. M. Cell biology of cnidarian–dinoflagellate symbiosis. Microbiol. Mol. Biol. Rev. 76, 229–261 (2012).
2. Wakefield, T. S. & Kempf, S. C. Development of host-and symbiont-specific monoclonal antibodies and confirmation of the origin of the symbiosome membrane in a cnidarian–dinoflagellate symbiosis. Biol. Bull. 200, 127–143 (2001).
3. Jones, R. J. & Yellowlees, D. Regulation and control of intracellular algae (= zooxanthellae) in hard corals. Philos. Trans. R. Soc. Lond. B. 352, 457–468 (1997).
4. Hoegh-Guldberg, O. & Smith, G. J. Influence of the population density of zooxanthellae and supply of ammonium on the biomass and metabolic characteristics of the reef corals Seriatopora hystrix and Stylophora pistillata. Mar. Ecol. Prog. Ser. 57, 173–186 (1989).
5. Hoegh-Guldberg, O. The population dynamics of symbiotic zooxanthellae in the coral Pocillopora damicornis exposed to elevated ammonium (NH 4 Cl) concentrations. Pac. Sci. 48, 263–272 (1994).
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