Identification of cis-elements regulating expression of Fgf10 during limb development.
Fibroblast growth factor 10 (FGF10) is known to be expressed in limb mesenchymal cells and to function as a mesenchymal signaling factor involved in epithelial-mesenchymal interactions during limb development. To elucidate regulation of Fgf10 expression, we isolated the promoter region of Fgf10 containing its 2.0 kb upstream 5'-fragment from the initiation codon and its 0.9 kb downstream fragment. Transcriptional activity of the fragment was examined with transgenic mice, using a lacZ-reporter system. Although no significant expression of the reporter gene was observed for the 0.2 kb 5'-fragment, expression was detected in the apical ectodermal ridge of the limb bud and developing cartilage of the limb for the 2.0 kb and 0.7 kb 5'-fragments, respectively. From comparison of the mouse sequences of the 2.0 kb fragment with corresponding sequences of human and chicken Fgf10, we identified 17 conserved putative enhancer motifs for AER expression and other unidentified expressions. For limb cartilage expression, we found putative enhancer sequences conserved among the three species in the 0.7 kb 5'-fragment. In the fragment, three DNA binding motifs were identified in the mouse and human sequence, although they are not conserved in the corresponding chicken sequence.
Sasak
Hidemi
H
Department of Biological Science and Technology, Faculty of Engineering, The University of Tokushima, Tokushima City, Japan.
Yamaoka
Takashi
T
Ohuchi
Hideyo
H
Yasue
Akihiro
A
Nohno
Tsutomu
T
Kawano
Hirotaka
H
Kato
Shigeaki
S
Itakura
Mitsuo
M
Nagayama
Masaru
M
Noji
Sumihare
S
D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo; D017124:Conserved Sequence; D005121:Extremities / Q000196:embryology*; D051526:Fibroblast Growth Factor 10; D005346:Fibroblast Growth Factors / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D017930:Genes, Reporter; D006801:Humans; D051379:Mice; D008822:Mice, Transgenic; D011401:Promoter Regions, Genetic
C496463:FGF10 protein, human; C496464:Fgf10 protein, mouse; D051526:Fibroblast Growth Factor 10; D005346:Fibroblast Growth Factors