Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany. albina.asadulina@tuebingen.mpg.de.|Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany. markus.conzelmann@tuebingen.mpg.de.|Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany. elizabeth.williams@tuebingen.mpg.de.|Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany. aurora.panzera@tuebingen.mpg.de.|Max Planck Institute for Developmental Biology, Spemannstrasse 35, 72076, Tübingen, Germany. gaspar.jekely@tuebingen.mpg.de.