2007 Fiscal Year Final Research Report Summary
Involvement of Tsukushi in chick early embryogenesis
Project/Area Number |
17370082
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Research Category |
Grant-in-Aid for Scientific Research (B)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Developmental biology
|
Research Institution | Kumamoto University |
Principal Investigator |
OHTA Kunimasa Kumamoto University, Department of Developmental Nuerobiology Graduate School of Medical Sciences, Associate Professor (90244128)
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Co-Investigator(Kenkyū-buntansha) |
TANAKA Hideaki Kumamoto University, Department of Developmental Neurobiology Graduate School of Medical Sciences, Professor (90106906)
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Project Period (FY) |
2005 – 2007
|
Keywords | Differentiation and Development / Tsukushi / BMP antagonist / chick embryo |
Research Abstract |
Wnt signaling orchestrates multiple aspects of central nervous system development, including cell proliferation and cell fate choices. In chick retina, Wnt2b is expressed in both the surface ectoderm and the retinal pigmented epithelium at optic cup stage. At later stage, Wnt2b is expressed in the margin almost tip of the embryonic chick retina. Using a clonal assay in retinal re-aggregation cultures, along with overexpression studies, it was proposed that Wnt2b plays a role in the maintenance and the proliferation of retinal progenitor cells without cell differentiation (Kubo, et. al., 2005). We have identified a BMP antagonist, Tsukushi (TSK), which is a soluble molecule containing 12 leucine-rich repeats and belongs to the Small Leucine-Rich Proteoglycan family. TSK is expressed in the primitive streak and Hensen's node during chick gastrulation and involved in their formation (Ohta, et. al., 2004 ; Ohta, et. al., 2006). TSK is also involved in the neural crest specification of Xenopus embryo by regulating BMP and Delta-1 activities at the boundary between the neural and the non-neural ectoderm (Kuriyama, et. al., 2006). When Wnt2b was over-expressed into chick optic vesicle at stage 10, Wnt2b induced prolonged proliferation of retinal progenitor cells in vitro. However, when Wnt2b was co-over-expressed with TSK, the proliferative activity of Wnt2b was almost inhibited. We now show that TSK, which is expressed in the ciliary marginal zone (CMZ) of chick retina, inhibits the retinal progenitor cells proliferation by functioning as Wnt signaling inhibitor.
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Research Products
(37 results)