@booklet {krinos_intraspecific_2024,
	title = {Intraspecific diversity in thermal performance determines phytoplankton ecological niche},
	year = {2024},
	month = {feb},
	publisher = {Ecology},
	type = {preprint},
	abstract = {Abstract Temperature has a primary influence on phytoplankton physiology and affects biodiversity and ecology. To examine how intraspecific diversity and temperature shape plankton populations, we grew 12 strains of the ecologically-important coccolithophore Gephyrocapsa huxleyi isolated from regions of different temperature for \~{}45 generations (2 months), each at 6-8 temperatures, and characterized the acclimated thermal response curve of each strain. Even with virtually identical temperature optima and overlapping cell size, strain growth rates varied between 0.45 and 1 day -1 . While some thermal curves were effectively symmetrical, others had more slowly declining growth rates above the {\textquotedblleft}thermal optimum,{\textquotedblright} and thermal niche widths varied between 16.7 and 24.8 {\textdegree}C. This suggests that different strains use distinct thermal response mechanisms. We investigated the ecological implications of such intraspecific diversity on thermal response using an ocean ecosystem simulation resolving distinct phytoplankton thermal phenotypes. Resolving model analogs of thermal {\textquotedblleft}generalists{\textquotedblright} and {\textquotedblleft}specialists{\textquotedblright} (similar to those observed in G. huxleyi) resulted in a distinctive global biogeography of preferred thermal niche widths with a nonlinear latitudinal pattern. We leveraged the model output to predict the ranges of the 12 strains we studied in the laboratory and demonstrated how this approach could refine predictions of phytoplankton thermal geographic range in situ . Our combination of observed thermal traits and modeled biogeography highlights the capacity of diverse groups to persist through temperature shifts. Significance Statement Intraspecific diversity in the phytoplankton may underpin their distribution. We show that within a single coccolithophore species, thermal response curves have diverse trait parameters. For example, many strains had a variable range of temperatures at which they could survive (thermal niche width). Adding this thermal niche width diversity to an ecosystem model simulation impacted phytoplankton coexistence and overall biomass. These observations show that thermal niche width is a gap in phytoplankton representation in ecosystem models that impacts modeled phytoplankton biogeography and concomitant carbon cycle dynamics. Including thermal tolerance is crucial to predictive modeling as ocean temperature dynamics change.},
	keywords = {rcc1212, RCC3492, RCC3963, RCC4567, RCC6071, RCC874, RCC914},
	doi = {10.1101/2024.02.14.580366},
	url = {http://biorxiv.org/lookup/doi/10.1101/2024.02.14.580366},
	author = {Krinos, Arianna I. and Shapiro, Sara K. and Li, Weixuan and Haley, Sheean T. and Dyhrman, Sonya T. and Dutkiewicz, Stephanie and Follows, Michael J. and Alexander, Harriet}
}
@article {Hennon2017,
	title = {Diverse CO2-Induced responses in physiology and gene expression among eukaryotic phytoplankton},
	journal = {Frontiers in Microbiology},
	volume = {8},
	number = {December},
	year = {2017},
	note = {tex.mendeley-tags: RCC1303},
	month = {dec},
	pages = {1{\textendash}14},
	abstract = {With rising atmospheric CO2, phytoplankton face shifts in ocean chemistry including increased dissolved CO2 and acidification that will likely influence the relative competitive fitness of different phytoplankton taxa. Here we compared the physiological and gene expression responses of six species of phytoplankton including a diatom, a raphidophyte, two haptophytes, and two dinoflagellates to ambient (\~400 ppm) and elevated (\~800 ppm) CO2. Dinoflagellates had significantly slower growth rates and higher, yet variable, chlorophyll a per cell under elevated CO2. The other phytoplankton tended to have increased growth rates and/or decreased chlorophyll a per cell. Carbon and nitrogen partitioning of cells shifted under elevated CO2 in some species, indicating potential changes in energy fluxes due to changes in carbon concentrating mechanisms (CCM) or photorespiration. Consistent with these phenotypic changes, gene set enrichment analyses revealed shifts in energy, carbon and nitrogen metabolic pathways, though with limited overlap between species in the genes and pathways involved. Similarly, gene expression responses across species revealed few conserved CO2-responsive genes within CCM and photorespiration categories, and a survey of available transcriptomes found high diversity in biophysical CCM and photorespiration expressed gene complements between and within the four phyla represented by these species. The few genes that displayed similar responses to CO2 across phyla were from understudied gene families, making them targets for further research to uncover the mechanisms of phytoplankton acclimation to elevated CO2. These results underscore that eukaryotic phytoplankton have diverse gene complements and gene expression responses to CO2 perturbations and highlight the value of cross-phyla comparisons for identifying gene families that respond to environmental change.},
	keywords = {algae, biophysical CCM, C4 CCM, carbon concentrating mechanism, carbon concentrating mechanism (CCM), ccm, photorespiration, RCC1303, transcriptomics},
	issn = {1664-302X},
	doi = {10.3389/fmicb.2017.02547},
	url = {http://journal.frontiersin.org/article/10.3389/fmicb.2017.02547/full},
	author = {Hennon, Gwenn M. M. and Hern{\'a}ndez Lim{\'o}n, Mar{\'\i}a D. and Haley, Sheean T. and Juhl, Andrew R. and Dyhrman, Sonya T.}
}
