Institute of Development, Aging and Cancer, Tohoku University


Seminars and Symposia

IDAC Seminar, 5 October 2011

Secretariat, Alumni Association, IDAC
Date Wednesday, 5 October 2011, 16:00~
Room Kokusai-kaigi-shitsu, IDAC Smart Ageing International Research Center First floor
Title Tbx6-dependent regulation of Sox2 determines neural versus mesodermal fate in axial stem cells.
Speaker Tatsuya Takemoto
Affiliation Graduate School of Frontier Biosciences, Osaka University
Person-in-charge Yasuhisa Matsui Cell Resource Center for Biomedical Research (ex 8571)
Abstract Axial elongation of vertebrate embryos involves two major processes: head formation and extension of the posterior end of embryo. Previous cell lineage studies suggested that the axial stem cells, the cellular source for the posterior embryo extension, are localized in caudal lateral epiblast, and serve as common precursors for the neural plate and paraxial mesoderm. I demonstrated that the counteraction of transcription factors SOX2 and TBX6 determines the neural versus mesodermal fate choice in the axial stem cells.
Sox2 enhancer N1 is activated in the axial stem cells in the caudal lateral epiblast, and the cells staying the superficial layer initiate Sox2 expression and become the neural plate. In normal embryos, this enhancer N1 activity is turned off in the population of axial stem cells that has migrated through the primitive streak. In Tbx6 mutant embryos, however, the enhancer N1-activity is maintained in the paraxial mesoderm, leading to ectopic Sox2 activation and ectopic neural tube development. Deletion of enhancer N1 from the Sox2 locus prevented the development of ectopic neural tube.