In myoblast cell cultures, the Msx1 protein is able to repress myogenesis and maintain cells in an undifferentiated and proliferative state. However, there has been no evidence that Msx1 is expressed in muscle or its precursors in vivo. Using mice with the nlacZ gene integrated into the Msx1 locus, we show that the reporter gene is expressed in the lateral dermomyotome of brachial and thoracic ...

NKL homeobox gene MSX1 is physiologically expressed in lymphoid progenitors and subsequently downregulated in developing T- and B-cells. In contrast, elevated expression levels of MSX1 persist in mature natural killer (NK)-cells, indicating a functional role in this compartment. While T-cell acute lymphoblastic leukemia (T-ALL) subsets exhibit aberrant overexpression of MSX1, we show here that ...

Epidermal fate in Xenopus ectoderm has been shown to be induced by a secreted growth factor, Bone Morphogenetic Protein 4 (BMP4). However, the molecular mechanism mediating this response is poorly understood. Here, we show that the expression of the homeobox gene, msx1, is an immediate early response to BMP4 in Xenopus embryos. The timing of expression and embryonic distribution of msx1 paralle...

We have generated a null allele of the mouse Msx1 homeobox gene by insertion of an nlacZ reporter gene into its homeobox. The sensitivity of beta-galactosidase detection permitted us to reveal novel aspects of Msx1 gene expression in heterozygous embryos, in particular in ectoderm and mesoderm during gastrulation, and in migrating neural crest cells. Homozygous mutant mice die at birth with fac...

The regeneration of digit tips in mammals, including humans and rodents, represents a model for organ regeneration in higher vertebrates. We had previously characterized digit tip regeneration during fetal and neonatal stages of digit formation in the mouse and found that regenerative capability correlated with the expression domain of the Msx1 gene. Using the stage 11 (E14.5) digit, we now sho...

Bmp4 is a downstream gene of Msx1 in early mouse tooth development. In this study, we introduced the Msx1-Bmp4 transgenic allele to the Msx1 mutants in which tooth development is arrested at the bud stage in an effort of rescuing Msx1 mutant tooth phenotype in vivo. Ectopic expression of a Bmp4 transgene driven by the mouse Msx1promoter in the dental mesenchyme restored the expression of Lef-1 ...

In the developing mammalian tooth, the cranial neural crest derived dental mesenchyme consists of the dental papilla and dental follicle. The dental papilla gives rise to odontoblasts and dental pulp and the dental follicle gives rise to the periodontium, including the osteoblasts that contribute to the alveolar process. The alveolar process is a specialized intramembranous bone that forms the ...

Our studies are aimed at identifying the transcription factors that activate the glycoprotein hormone alpha-subunit promoter. Therefore, we performed a Southwestern screening of a thyrotropic (alphaTSH) cDNA expression library, using the region of the promoter from -490 to -310 that contains sequences critical for expression in thyrotrope cells. A clone was isolated corresponding to part of the...

During early tooth development, multiple signaling molecules are expressed in the dental lamina epithelium and induce the dental mesenchyme. One signal, BMP4, has been shown to induce morphologic changes in dental mesenchyme and mesenchymal gene expression via Msx1, but BMP4 cannot substitute for all the inductive functions of the dental epithelium. To investigate the role of FGFs during early ...

Collateral remodeling is critical for blood flow restoration in peripheral arterial disease and is triggered by increasing fluid shear stress in preexisting collateral arteries. So far, no arterial-specific mediators of this mechanotransduction response have been identified. We show that muscle segment homeobox 1 (MSX1) acts exclusively in collateral arterial endothelium to transduce the extrin...