Type
Text
Type
Thesis
Advisor
Sirotkin, Howard. | Martin, Benjamin L
Date
2015-12-01
Keywords
Biochemistry | development, fate sepcification, sox2, stem cell, Wnt
Department
Department of Biochemistry and Cell Biology.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76931
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
During vertebrate development, formation of the head -to-tail body axis is shaped by a group of unspecified cells at the caudal region of the embryo. The undifferentiated tail bud stem cells are capable of adopting mesodermal or neural cell fates as the embryo develops, but the mechanism of this patterning process remains largely unknown. Our previous studies confirm that Wnt signaling is required in tail bud stem cells to repress the neural transcription factor sox2 and induce mesodermal fate. However, it is unclear if sox2 repression at the cell-autonomous level is the critical factor required for Wnt mediated mesoderm induction. Using zebrafish transgenic lines, we reveal that downregulation of sox2 is necessary for mesodermal progenitors to exit the tail bud. Surprisingly, we also find that ectopic sox2 can induce neural tissue in cells normally destined to give rise to somites in a Wnt signaling-dependent manner. Constitutive expression of Wnt represses sox2 expression and promotes adaption of mesodermal fate, whereas overexpression of sox2 downregulates Wnt pathway activity, inducing neural fate adaption. Moreover, simultaneous high level of Wnt signaling and high level of sox2 promotes the long term bipotential state of tailbud stem cells. Together our results reveal the requirement of precise regulation of differential expression levels of sox2 and Wnt pathway in proper tissue patterning during embryo development. | 35 pages
Recommended Citation
Tseng, Yu-Jung, "The roles of sox2 and canonical Wnt signaling pathway in fate specification of tailbud bipotential stem cells" (2015). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2804.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2804