@article {ben-joseph_crystallization_2023,
	title = {Crystallization of Coccolith Calcite at Different Life-Cycle Phases Exhibits Distinct Degrees of Cellular Confinement},
	journal = {Small Structures},
	volume = {n/a},
	number = {n/a},
	year = {2023},
	note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/sstr.202200353},
	pages = {2200353},
	abstract = {Coccolithophores are a group of unicellular marine algae that shape global geochemical cycles via the production of calcium carbonate crystals. Interestingly, different life-cycle phases of the same coccolithophore species produce very different calcitic scales, called coccoliths. In the widely studied diploid phase, the crystals have anisotropic and complex morphologies, while haploid cells produce coccoliths consisting solely of calcite crystals with simple rhombohedral morphology. Understanding how these two life-cycle phases control crystallization is a highly sought-after goal, yet, haploid phase crystallization has rarely been studied, and the process by which they form is unknown. Herein, advanced electron microscopy is employed to elucidate the cellular architecture of the calcification process in haploid cells. The results show that in contrast to diploid-phase calcification, the coccolith-forming vesicle of haploid-phase cells is voluminous. In this solution-like environment, the crystals nucleate and grow asynchronously in a process that resembles calcite growth in bulk solution, leading to the simple morphologies of the crystals. The two distinct mineralization regimes of coccolithophore life-cycle phases suggest that cellular architecture, and specifically confinement of the crystallization process, is a pivotal determinant of biomineral morphology and assembly.},
	keywords = {biomineralization, calcites, Coccoliths, crystal growths, haploid{\textendash}diploid life cycles, RCC1181, RCC3777},
	issn = {2688-4062},
	doi = {10.1002/sstr.202200353},
	url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/sstr.202200353},
	author = {Ben-Joseph, Oz and de Haan, Diede and Rechav, Katya and Shimoni, Eyal and Levin-Zaidman, Smadar and Langer, Gerald and Probert, Ian and Wheeler, Glen L. and Gal, Assaf}
}
@article {eyal_variability_2022,
	title = {The variability in the structural and functional properties of coccolith base plates},
	journal = {Acta Biomaterialia},
	volume = {148},
	year = {2022},
	pages = {336{\textendash}344},
	abstract = {Biomineralization processes exert varying levels of control over crystallization, ranging from poorly ordered polycrystalline arrays to intricately shaped single crystals. Coccoliths, calcified scales formed by unicellular algae, are a model for a highly controlled crystallization process. The coccolith crystals nucleate next to an organic oval structure that was termed the base plate, leading to the assumption that it is responsible for the oriented nucleation of the crystals via stereochemical interactions. In recent years, several works focusing on a well-characterized model species demonstrated a fundamental role for indirect interactions that facilitate coccolith crystallization. Here, we developed the tools to extract the base plates from five different species, giving the opportunity to systematically explore the relations between base plate and coccolith properties. We used multiple imaging techniques to evaluate the structural and chemical features of the base plates under native hydrated conditions. The results show a wide range of properties, overlaid on a common rudimentary scaffold that lacks any detectable structural or chemical motifs that can explain direct nucleation control. This work emphasizes that it is the combination between the base plate and the chemical environment inside the cell that cooperatively facilitate the exquisite control over the crystallization process. Statement of significance Biological organic scaffolds can serve as functional surfaces that guide the formation of inorganic materials. However, in many cases the specific interactions that facilitate such tight regulation are complex and not fully understood. In this work, we elucidate the architecture of such amodel biological template, an organic scale that directs the assembly of exquisite crystalline arrays of marine microalgae. By using cryo electron microscopy, we reveal the native state organization of these scales from several species. The observed similarities and differences allow us to propose that the chemical microenvironment, rather than stereochemical matching, is the pivotal regulator of the process.},
	keywords = {biomineralization, Calcite, Coccoliths, Cryo electron tomography, Crystallization, RCC1130, RCC1181, RCC190, RCC3777},
	issn = {1742-7061},
	doi = {10.1016/j.actbio.2022.06.027},
	url = {https://www.sciencedirect.com/science/article/pii/S174270612200366X},
	author = {Eyal, Zohar and Krounbi, Leilah and Ben Joseph, Oz and Avrahami, Emanuel M. and Pinkas, Iddo and Peled-Zehavi, Hadas and Gal, Assaf}
}
