Roles of Zic family in neural development

s42

Mini-Symposium Mechanisms

MS08- 1

YOSHIKI

08

of the pattern formation

THE NEURAL

INDUCER

CHORDIN

of the central nervous system

AND ITS DOWNSTREAM

GENES

SASAI

Department of Medical Embryology PRESTO. JST

and Neurobiology,

Inst. for Frontier Medical

Sciences,

Kyoto Univ.

Vertebrate nervous systems are formed from embryonic ectoderm by complicated tissue interactions during early embryogenesis. Most importantly, the signals emanating from the organizer (Neural inducer) play a crutial role in this process. Recent studies using molecular techniques have identified several organizer-derived neural inducers in Xenopus We isolated the neural inducer Chrodin which can induce neural differentiation in isolated embryonic ectoderm. Chordin functions by antagonizing the anineuralizing factor BMP-4. In this talk, I would like to review recent progress in neural induction reseach. In addition, our recent data on downstream factors of Chordin and their roles in the forming CNS

MS08-2

ROLES OF ZIG FAMILY IN NEURAL DEVELOPMENT

JUN ARUGA. TAKEHARU AND KATSUHIKO

NAGAI, KATSUNORI

Molecular Neurobiology

Laboratory

KITAGUCHI,

KIYOMI MIZUGISHI,

Ibaraki 305-0074

in the mouse cerebellar granule cell lineage. The Zic genes

factors with zinc finger motifs. We previously showed that the genes are vertebrate homologues

of Drosophila pair-rule gene, odd-@red

and that the zinc finger motifs of Zic proteins are highly similar to those of

Gli proteins. which has been characterized

as a factor involved in the Sonic hedgehog

To reveal the role of Zic family in neural development,

we performed

analyses in mouse, frog and chick embryos. These studies neural development,

TETSUYA

and Brain Science Institute, RIKEN, Tsukuba-shi,

Zic family was found as being expressed abundantly encode transcription

NAKATA,

MIKOSHIBA

such as neuroectoderm

loss-of-function

medlated signaling cascade. and gain-of-function

revealed that the 2%. family has multiple roles in the

and neural crest formation, cerebellar patterning.

regulatory factors involved in the Zic expression

Studies on the

and.the target genes of the Zic proteins are currently in progress.