TY - JOUR
T1 - Level-specific role of paraxial mesoderm in regulation of Tbx5/Tbx4 expression and limb initiation
AU - Saito, Daisuke
AU - Yonei-Tamura, Sayuri
AU - Takahashi, Yoshiko
AU - Tamura, Koji
N1 - Funding Information:
We thank Dr. Juan Carlos Izpisua Belmonte and Dr. Yasuhiko Kawakami (The Salk institute, USA) for kind gifts of the Tbx5, Tbx4, Pitx1 and Wnt2b probes. We also thank Dr. Hiroyuki Ide for critical comments on the manuscript. This work was supported by research grants from the Ministry of Education, Science, Sports and Culture of Japan.
PY - 2006/4/1
Y1 - 2006/4/1
N2 - Tetrapod limbs, forelimbs and hindlimbs, emerge as limb buds during development from appropriate positions along the rostro-caudal axis of the main body. In this study, tissue interactions by which rostro-caudal level-specific limb initiation is established were analyzed. The limb bud originates from the lateral plate located laterally to the paraxial mesoderm, and we obtained evidence that level-specific tissue interactions between the paraxial mesoderm and the lateral plate mesoderm are important for the determination of the limb-type-specific gene expression and limb outgrowth. When the wing-level paraxial mesoderm was transplanted into the presumptive leg region, the wing-level paraxial mesoderm upregulated the expression of Tbx5, a wing marker gene, and downregulated the expression of Tbx4 and Pitx1, leg marker genes, in the leg-level lateral plate. The wing-level paraxial mesoderm relocated into the leg level also inhibited outgrowth of the hindlimb bud and downregulated Fgf10 and Fgf8 expression, demonstrating that the wing-level paraxial mesoderm cannot substitute for the function of the leg-level paraxial mesoderm in initiation and outgrowth of the hindlimb. The paraxial mesoderm taken from the neck- and flank-level regions also had effects on Tbx5/Tbx4 expression with different efficiencies. These findings suggest that the paraxial mesoderm has level-specific abilities along the rostro-caudal axis in the limb-type-specific mechanism for limb initiation.
AB - Tetrapod limbs, forelimbs and hindlimbs, emerge as limb buds during development from appropriate positions along the rostro-caudal axis of the main body. In this study, tissue interactions by which rostro-caudal level-specific limb initiation is established were analyzed. The limb bud originates from the lateral plate located laterally to the paraxial mesoderm, and we obtained evidence that level-specific tissue interactions between the paraxial mesoderm and the lateral plate mesoderm are important for the determination of the limb-type-specific gene expression and limb outgrowth. When the wing-level paraxial mesoderm was transplanted into the presumptive leg region, the wing-level paraxial mesoderm upregulated the expression of Tbx5, a wing marker gene, and downregulated the expression of Tbx4 and Pitx1, leg marker genes, in the leg-level lateral plate. The wing-level paraxial mesoderm relocated into the leg level also inhibited outgrowth of the hindlimb bud and downregulated Fgf10 and Fgf8 expression, demonstrating that the wing-level paraxial mesoderm cannot substitute for the function of the leg-level paraxial mesoderm in initiation and outgrowth of the hindlimb. The paraxial mesoderm taken from the neck- and flank-level regions also had effects on Tbx5/Tbx4 expression with different efficiencies. These findings suggest that the paraxial mesoderm has level-specific abilities along the rostro-caudal axis in the limb-type-specific mechanism for limb initiation.
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U2 - 10.1016/j.ydbio.2006.01.002
DO - 10.1016/j.ydbio.2006.01.002
M3 - Article
C2 - 16480709
AN - SCOPUS:33646459228
SN - 0012-1606
VL - 292
SP - 79
EP - 89
JO - Developmental Biology
JF - Developmental Biology
IS - 1
ER -