Gene regulatory network involved in the notochord formation in the Ciona intestinalis embryo Nori Satoh Marine Genomics Unit, Okinawa Institute of Science and Technology The notochord is a most prominent feature of chordates. An elucidation of molecular mechanisms involved in the formation of notochord in ascidian (urochordate) embryos is therefore essential for better understanding not only of its differentiation mechanism but also the origin and evolution of chordates. The ascidian larva develops the notochord that consists of exactly 40 cells, of which lineage is completely documented. A member of T-box family transcription factor genes, Brachyury, is a key regulator for the notochord formation. Its zygotic expression commences at the 64-cell stage when A-line cells are destined to give rise to only notochord. The upstream cascade leading to Ci-Bra (Brachyury of Ciona intestinalis) includes maternal b-catenin and p53, and zygotic FoxD, FGF and ZicL. The downstream cascade of Ci-Bra includes ~400 genes involved in the notochord formation. We wish to discuss the complexity of gene regulatory network responsible for the notochord formation in ascidian embryos.

Gene regulatory network involved in the notochord formation in the Ciona intestinalis embryo

Nori Satoh

Marine Genomics Unit, Okinawa Institute of Science and Technology

The notochord is a most prominent feature of chordates. An elucidation of molecular mechanisms involved in the formation of notochord in ascidian (urochordate) embryos is therefore essential for better understanding not only of its differentiation mechanism but also the origin and evolution of chordates. The ascidian larva develops the notochord that consists of exactly 40 cells, of which lineage is completely documented. A member of T-box family transcription factor genes, Brachyury, is a key regulator for the notochord formation. Its zygotic expression commences at the 64-cell stage when A-line cells are destined to give rise to only notochord. The upstream cascade leading to Ci-Bra (Brachyury of Ciona intestinalis) includes maternal b-catenin and p53, and zygotic FoxD, FGF and ZicL. The downstream cascade of Ci-Bra includes ~400 genes involved in the notochord formation. We wish to discuss the complexity of gene regulatory network responsible for the notochord formation in ascidian embryos.