新学術領域研究
「ミクロからマクロへ階層を超える秩序形成」
テクニカルセミナー
Dr. Noriaki Sasai
Post-doctoral fellow
MRC, National Institute for Medical Research, London,
United Kingdom
Sonic Hedgehog and its transcriptional network
control neural tube pattern formation
11 月 20 日（火）17:00 – 18:00
東京大学・理学部 2 号館講堂（4F）
The development of the central nervous system starts with the formation of the neural tube.
Molecularly distinct domains of progenitors are arrayed along the dorsal ventral axis of this tube
and each domain generates functionally distinct neuronal subtypes. This regionalisation is
achieved, in part, by the action of the morphogens – secreted molecules that act in a graded
manner to control differential gene expression. We are particularly interested in the ventral part
of the trunk neural tube, which generates the motor neurons and interneurons that coordinate
motor output. Here pattern formation is mainly governed by the secreted factor Sonic Hedgehog
(Shh). We have found that both the concentration and duration of Shh signalling contribute to
pattern formation and our data indicates that Shh induces a set of downstream transcription
factors that form a network resulting in the spatial-temporal patterns of gene expression.
Furthermore, the timing of signaling is also important to the patterning of the neural tube. In
particular, the most ventral part of the neural tube, which forms the floor plate, requires
exposure to Shh at early developmental times. This limited responding time window, or
competence for floor plate induction, is determined by FGF signaling. We are dissecting the
transcriptional network downstream of FGF, and are unraveling how the networks controlled by
Shh and FGF cooperate to define floor plate identity. Together, the interplay between the input
by Shh and the competence of the recipient neural progenitor cells provide the stereotyped and
precise patterning of the developing neural tube.
References
1. Dessaud et al. PLoS Biology (2010) vol. 8, e1000382
2. Ribes et al. Genes and Development (2010) vol. 24, 1186-1200
お問い合わせ：武田洋幸（東大・院理・生科、03-5841-4431）