Korean J Anat.
2005 Feb;38(1):93-102.
Roles of Gli3 in the Establishment of Progenitor Domains of Developing Spinal Cord
- Affiliations
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- 1Department of Anatomy, College of Medicine, Pusan National University, Korea. kimjb@pusan.ac.kr
Abstract
- University Sonic hedgehog (Shh) signaling has been shown to play instructive roles in developing spinal cord. Depending on the Shh concentration gradient, different progenitor domains and ventral neurons are induced. However, the way how the Shh gradient is translated into different progenitor domains, is not clear. To investigate the translation of the Shh gradient, we studied expressions of homeoproteins which are critical for establishment of progenitor domains, in the ventral neural tube of Shh(-/-)and Shh(-/-);Gli3(-/-) mutants, using in situ hybridization. In Shh(-/-) mutant, the expressions of class II homeoproteins (Nkx6.1, Nkx6.2, Olig2, Nkx2.2 were totally repressed. The expressions of class I homeoproteins (Dbx1, Dbx2, Irx3, Pax6 were ventralized. In Shh(-/-);Gli3(-/-) mutant, the expressions of class II homeoproteins except Nkx2.2 were restored. The expressions of class I home-oproteins were restored to its original position although their restoration is not complete. From above results, we conclude that Gli3 can regulate the expressions of class II homeoproteins, which suggests that the Shh gradient will be translated into Gli activity in the developing spinal cord.
