Olaf Bergmann1,*, Ratan D. Bhardwaj1,*, Samuel Bernard2, Sofia Zdunek1, Fanie Barnabé-Heider1, Stuart Walsh3, Joel Zupicich1, Kanar Alkass4, Bruce A. Buchholz5, Henrik Druid4, Stefan Jovinge3,6, Jonas Frisén1,†1 Department of Cell and Molecular Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden.2 CNRS UMR5208, Institut Camille Jordan, Université Claude Bernard Lyon 1, 69622 Villeurbanne c