Department of Protein Evolution, Max-Planck-lnstitute for Developmental Biology, Spemannstrasse 35, D-72076 Tübingen, Germany. manju@tuebingen.mpg.de <manju@tuebingen.mpg.de>|Department of Protein Evolution, Max-Planck-lnstitute for Developmental Biology, Spemannstrasse 35, D-72076 Tübingen, Germany. manju@tuebingen.mpg.de <manju@tuebingen.mpg.de>|Department of Protein Evolution, Max-Planck-lnstitute for Developmental Biology, Spemannstrasse 35, D-72076 Tübingen, Germany. manju@tuebingen.mpg.de <manju@tuebingen.mpg.de>