Zinc Dynamics during Drosophila Oocyte Maturation and Egg Activation
Qinan Hu,
Francesca E. Duncan,
Andrew B. Nowakowski,
Olga A. Antipova,
Teresa K. Woodruff,
Thomas V. O'Halloran,
Mariana F. Wolfner
Affiliations
Qinan Hu
Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
Francesca E. Duncan
Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
Andrew B. Nowakowski
The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA; Department of Chemistry, Northwestern University, Evanston, IL 60208, USA
Olga A. Antipova
X-ray Sciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
Teresa K. Woodruff
Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA; The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA; Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA; Corresponding author
Thomas V. O'Halloran
The Chemistry of Life Processes Institute, Northwestern University, Evanston, IL 60208, USA; Department of Chemistry, Northwestern University, Evanston, IL 60208, USA; Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA; Corresponding author
Mariana F. Wolfner
Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA; Corresponding author
Summary: Temporal fluctuations in zinc concentration are essential signals, including during oogenesis and early embryogenesis. In mammals, zinc accumulation and release are required for oocyte maturation and egg activation, respectively. Here, we demonstrate that zinc flux occurs in Drosophila oocytes and activated eggs, and that zinc is required for female fertility. Our synchrotron-based X-ray fluorescence microscopy reveals zinc as the most abundant transition metal in Drosophila oocytes. Its levels increase during oocyte maturation, accompanied by the appearance of zinc-enriched intracellular granules in the oocyte, which depend on transporters. Subsequently, in egg activation, which mediates the transition from oocyte to embryo, oocyte zinc levels decrease significantly, as does the number of zinc-enriched granules. This pattern of zinc dynamics in Drosophila oocytes follows a similar trajectory to that in mammals, extending the parallels in female gamete processes between Drosophila and mammals and establishing Drosophila as a model for dissecting reproductive roles of zinc.
