title: Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks.
abstract: Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes.
authors.affiliation: The Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Emily L
authors.initials: EL
authors.lastname: Que
authors.affiliation: 1] The Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA [2] Northwestern University Atomic and Nanoscale Characterization Experimental Center, Evanston, Illinois 60208, USA.
authors.forename: Reiner
authors.initials: R
authors.lastname: Bleher
authors.affiliation: Department of Obstetrics and Gynecology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Francesca E
authors.initials: FE
authors.lastname: Duncan
authors.affiliation: Department of Obstetrics and Gynecology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA.
authors.forename: Betty Y
authors.initials: BY
authors.lastname: Kong
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Sophie C
authors.initials: SC
authors.lastname: Gleber
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Stefan
authors.initials: S
authors.lastname: Vogt
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Si
authors.initials: S
authors.lastname: Chen
authors.affiliation: 1] The Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA [2] Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Seth A
authors.initials: SA
authors.lastname: Garwin
authors.affiliation: 1] The Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA [2] Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Amanda R
authors.initials: AR
authors.lastname: Bayer
authors.affiliation: 1] Northwestern University Atomic and Nanoscale Characterization Experimental Center, Evanston, Illinois 60208, USA [2] Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA [3] Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Vinayak P
authors.initials: VP
authors.lastname: Dravid
authors.affiliation: 1] The Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA [2] Department of Obstetrics and Gynecology, Northwestern University, Feinberg School of Medicine, Chicago, Illinois 60611, USA [3] Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Teresa K
authors.initials: TK
authors.lastname: Woodruff
authors.affiliation: 1] The Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, USA [2] Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA [3] Department of Molecular Biosciences, Northwestern University, Evanston, Illinois 60208, USA.
authors.forename: Thomas V
authors.initials: TV
authors.lastname: O'Halloran
mesh_terms: D000818:Animals; D048750:Cell Nucleus Division; D015342:DNA Probes / Q000378:metabolism; D005089:Exocytosis; D005260:Female; D005306:Fertilization; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry; D051379:Mice; D018613:Microscopy, Confocal; D017348:Microscopy, Electron, Scanning Transmission; D009865:Oocytes / Q000378:metabolism* / Q000648:ultrastructure; D015032:Zinc / Q000737:chemistry / Q000378:metabolism*
chemical_list: D015342:DNA Probes; D005456:Fluorescent Dyes; D015032:Zinc