Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (UP), Porto, Portugal. Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (UP), Porto, Portugal; Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, Porto, Portugal. Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (UP), Porto, Portugal; Department of Genetics, Faculty of Medicine, University of Porto, Porto, Portugal; Health Institute of Research and Innovation (IPATIMUP/i3S), University of Porto, Porto, Portugal. Centre for Reproductive Genetics A. Barros (CGR), Porto, Portugal. Department of Genetics, Faculty of Medicine, University of Porto, Porto, Portugal; Health Institute of Research and Innovation (IPATIMUP/i3S), University of Porto, Porto, Portugal; Centre for Reproductive Genetics A. Barros (CGR), Porto, Portugal. Laboratory of Cell Biology, Department of Microscopy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto (UP), Porto, Portugal; Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, Porto, Portugal. Electronic address: msousa@icbas.up.pt.