Max-Planck-Institute for Molecular Genetics, Berlin, Germany.|Max-Planck-Institute for Molecular Genetics, Berlin, Germany.|Max-Planck-Institute for Molecular Genetics, Berlin, Germany.|Max-Planck-Institute for Molecular Genetics, Berlin, Germany.|Max-Planck-Institute for Molecular Genetics, Berlin, Germany.|Max-Planck-Institute for Molecular Genetics, Berlin, Germany.