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Science 312 (5777): 1183-1187

Copyright © 2006 by the American Association for the Advancement of Science

Regulatory Blueprint for a Chordate Embryo

Kaoru S. Imai,1 Michael Levine,2 Nori Satoh,1 Yutaka Satou1*

Abstract: Ciona is an emerging model system for elucidating gene networks in development. Comprehensive in situ hybridization assays have identified 76 regulatory genes with localized expression patterns in the early embryo, at the time when naïve blastomeres are determined to follow specific cell fates. Systematic gene disruption assays provided more than 3000 combinations of gene expression profiles in mutant backgrounds. Deduced gene circuit diagrams describing the formation of larval tissues were computationally visualized. These diagrams constitute a blueprint for the Ciona embryo and provide a foundation for understanding the evolutionary origins of the chordate body plan.

1 Department of Zoology, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
2 epartment of Molecular and Cellular Biology, Division of Genetics and Development, University of California, Berkeley, CA 94720, USA.

* To whom correspondence should be addressed. E-mail: yutaka{at}

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Science 312, 1145-1146
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