1 Laboratory of Genetics, Wageningen University and Research, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
2 Molecular Plant Physiology, Institute of Environmental Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
3 Theoretical Biology and Bioinformatics, Institute of Biodynamics and Biocomplexity, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
4 Swammerdam Institute for Life Sciences, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands. P.F.Fransz@uva.nl.