Roles of Gli3 in Dorsal Neural Tube

Oh, Sae Ock; Bae, Soo Kyung; Yoon, Sik; Baek, Sun Yong; Kim, Bong Seon; Kim, Jae Bong

Abstract

Essential roles of Gli3 in ventral neural tube have been stressed from studies of Shh(-/-) and Shh(-/-); Gli3(-/-) mutants. However, roles of Gli3 in dorsal neural tube have not been fully appreciated despite of its high expression. To find out roles of Gli3 in dorsal neural tube, we studied cell proliferation and neuronal differentiation in dorsal neural tube of Gli3(-/-) mutant. In Gli3(-/-) mutant, proliferation of progenitor cells in dorsal neural tube is increased compared to wild type embryos based on phosphohistone 3 immunohistochemistry and BrdU experiment. The appearances of HuC/D positive and Isl1 postive cells which represent postmitotic neurons and dI3 interneurons were delayed in Gli3(-/-) mutant compared to wild type embryo. The appearance of a proneural gene, Ngn2 was also delayed in Gli3(-/-) mutant compared to wild type embryo. Neuronal differentiation of progenitor cells in dorsal neural tube was delayed in Gli3(-/-) mutant compared to wild type embryos based on HuC/D, Isl1 and Ngn2 expressions. These results suggest that Gli3 plays important roles in cell proliferation and neuronal differentiation in dorsal neural tube. Thus our data shed a new light on the role of Gli3 in the development of neural tube.