1. Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom
2. Institute of Biology/Genetics, Martin Luther University, D-06120 Halle, Germany
3. Department of Genetics and Molecular Biology, University of Szeged, 6726 Szeged, Hungary
4. Institute of Biochemistry, Biological Research Center, Szeged H-6726, Hungary
5. Department of Molecular Biology, Umeå University, S-901 87 Umeå, Sweden
6. Zoologisches Institut der Universitat Zurich, 8057 Zurich, Switzerland
7. CIC Biogune, Parque Technologico de Bizkaia, Derio 48160, Spain
8. Institut für Genetik, Universität Mainz, 55128 Mainz, Germany
9. Department of Developmental Genetics, Deutsches Krebsforschungszentrum, D-69120 Heidelberg, Germany and
10. Departament de Genetica, Facultat de Biologia, Universitat de Barcelona, 08028 Barcelona, Spain