title: Biomineralization pathways in a foraminifer revealed using a novel correlative cryo-fluorescence-SEM-EDS technique.
abstract: Foraminifera are marine protozoans that are widespread in oceans throughout the world. Understanding biomineralization pathways in foraminifera is particularly important because their calcitic shells are major components of global calcium carbonate production. We introduce here a novel correlative approach combining cryo-SEM, cryo-fluorescence imaging and cryo-EDS. This approach is applied to the study of ion transport processes in the benthic foraminifer genus Amphistegina. We confirm the presence of large sea water vacuoles previously identified in intact and partially decalcified Amphistegina lobifera specimens. We observed relatively small vesicles that were labelled strongly with calcein, and also identified magnesium (Mg)-rich mineral particles in the cytoplasm, as well as in the large sea water vacuoles. The combination of cryo-microscopy with elemental microanalysis and fluorescence imaging reveals new aspects of the biomineralization pathway in foraminifera which are, to date, unique in the world of biomineralization. This approach is equally applicable to the study of biomineralization pathways in other organisms.
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel.
authors.forename: Gal Mor
authors.initials: GM
authors.lastname: Khalifa
authors.affiliation: Department of Materials and Interfaces, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Kirchenbuechler
authors.affiliation: Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel.
authors.forename: Naama
authors.initials: N
authors.lastname: Koifman
authors.affiliation: Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel.
authors.forename: Olga
authors.initials: O
authors.lastname: Kleinerman
authors.affiliation: Department of Chemical Engineering and the Russell Berrie Nanotechnology Institute (RBNI), Technion-Israel Institute of Technology, Haifa 3200003, Israel.
authors.forename: Yeshayahu
authors.initials: Y
authors.lastname: Talmon
authors.affiliation: Department of Materials and Interfaces, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel.
authors.forename: Michael
authors.initials: M
authors.lastname: Elbaum
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel.
authors.forename: Lia
authors.initials: L
authors.lastname: Addadi
authors.affiliation: Department of Structural Biology, Weizmann Institute of Science, 234 Herzl Street, Rehovot 7610001, Israel. Electronic address: Steve.weiner@weizmann.ac.il.
authors.forename: Steve
authors.initials: S
authors.lastname: Weiner
authors.affiliation: Institute of Earth Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Erez
mesh_terms: D002113:Calcification, Physiologic; D020285:Cryoelectron Microscopy; D056908:Foraminifera / Q000378:metabolism* / Q000648:ultrastructure; D017136:Ion Transport; D008274:Magnesium / Q000032:analysis; D053858:Metabolic Networks and Pathways; D008855:Microscopy, Electron, Scanning; D061848:Optical Imaging; D014617:Vacuoles
chemical_list: D008274:Magnesium
keywords: Biomineralization pathways; Correlative microscopy; Foraminifera; Magnesium; Shell formation