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ISSN 0582-9879 Acta Biochim et Biophysica Sinica 2004, 36(6):390-396 CN
31-1300/Q
Multiple Signaling Pathways Control Tbx6 Expression during Xenopus
Myogenesis
Pan-Feng FANG, Rui-Ying HU, Xing-Yue HE, and Xiao-Yan DING*
Laboratory of Molecular and Cell Biology,
Laboratory of Stem Cell Biology & Institute of Biochemistry and Cell
Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences,
Graduate School of the Chinese Academy of Sciences, Shanghai 200031, China
Abstract Tbx6 is critical for
somite specification and myogenesis initiation. It has been shown that Activin/Nodal,
VegT/Nodal, FGF, and BMP signaling pathways are involved early in specifying
mesoderm or later in patterning mesoderm, and Xnot plays roles in setting up
the boundary between notochord and paraxial mesoderm. In this study, we
introduce the dominant negative form of above genes into embryos to evaluate if
they are responsible for regulating Tbx6 expression. The results show that: (1)
Activin/Nodal and VegT/Nodal signals are necessary for both initiation and
maintenance of Tbx6 expression, and Nodal is sufficient to induce ectopic Tbx6
expression; (2) FGF signal is necessary for the initiation and maintenance of
Tbx6, but it is not sufficient to induce Tbx6 expression; (3) BMP is also
necessary for the expression of Tbx6, and the induction of Tbx6 expression by
BMP is dose dependent; (4) Xnot has no effect on the expression of Tbx6. Our
results suggest that several signaling pathways are involved in regulating Tbx6
expression, and pave the route to reveal the molecular mechanism of initiating
myogenesis.
Key words Tbx6; FGF; BMP;
Activin/Nodal; VegT/Nodal
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Received: April 21, 2004 Accepted: May 14, 2004
This work was supported by the grants from the National Natural
Science Foundation of China (30170111, 30270650) and the National Key Project
for Basic Science Research of China (2001CB509901)
*Corresponding author: Tel: 86-21-54921411; E-mail,
[email protected]