About the Authors
Hubrecht Laboratory, Utrecht, The Netherlands
Max-Delbruck-Center for Molecular Medicine (MDC), Berlin-Buch, Germany
The authors have declared that no competing interests exist.
VG and EC conceived and designed the experiments. VG, BMGS, JvdB, and MV performed the experiments. VG, BMGS, JvdB, and MV analyzed the data. VG and NH contributed reagents/materials/analysis tools. VG and EC wrote the paper.