1. The Mitochondrial and Reproductive Genetics Group, Division of Medical Sciences, University of Birmingham, Birmingham, United Kingdom.
2. Center for Neuroscience and Cell Biology, Department of Zoology, University of Coimbra, Coimbra, Portugal.
3. Pittsburgh Development Center, Magee-Women's Research Institute, Pittsburgh, Pennsylvania.
4. Departments of Obstetrics-Gynecology-Reproductive Sciences and Cell Biology-Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.