The development of many epithelial organs depends on a series of sequential and reciprocal interactions between epithelial cells and adjacent mesenchymal or stromal cells (Thesleff et al., 1995; Birchmeier and Birchmeier, 1993). The mammary gland is an example of an organ where these epithelialmesenchymal interactions play a critical role, especially during embryonic development (Sakakura, 1987...

The prostate gland develops from the fetal urogenital sinus at the base of the urinary bladder. It finally differentiates into three lobes; ventral, lateral and dorsal lobes of the prostate. In spite of their common developmental origin and similar glandular structure, these lobes show the different biochemical characteristics, for example, in the proteins they secrete. In the present study, we...

The development of the mammalian kidney, or metanephros, occurs in a region of posterior intermediate mesoderm by inductive interactions between the metanephric mesenchyme and the ureteric bud epithelium (Kuure et al., 2000; Lechner and Dressler, 1997; Schedl and Hastie, 2000). Induction of the mesenchyme by signals emanating from the bud initiates the aggregation of the mesenchyme and the conv...

Branching morphogenesis occurs during the development of many organs, and the embryonic mouse submandibular gland (SMG) is a classical model for the study of branching morphogenesis. In the developing SMG, this process involves iterative steps of epithelial bud and duct formation, to ultimately give rise to a complex branched network of acini and ducts, which serve to produce and modify/transpo...

Peripheral axons from auditory spiral ganglion neurons (SGNs) form an elaborate series of radially and spirally oriented projections that interpret complex aspects of the auditory environment. However, the developmental processes that shape these axon tracts are largely unknown. Radial bundles are comprised of dense SGN fascicles that project through otic mesenchyme to form synapses within the ...

Hematopoietic stem cells (HSCs) are produced by a small cohort of hemogenic endothelial cells (ECs) during development through the formation of intra-aortic hematopoietic cell (HC) clusters. The Runx1 transcription factor plays a key role in the EC-to-HC and -HSC transition. We show that Runx1 expression in hemogenic ECs and the subsequent initiation of HC formation are tightly controlled by th...

We asked whether specific mesenchymal/epithelial (M/E) induction generates olfactory receptor neurons (ORNs), vomeronasal neurons (VRNs), and gonadotropin-releasing hormone (GnRH) neurons, the major neuron classes associated with the olfactory epithelium (OE). To assess specificity of M/E-mediated neurogenesis, we compared the influence of frontonasal mesenchyme on frontonasal epithelium, which...

A common developmental process, called branching morphogenesis, generates the epithelial trees in a variety of organs, including lungs, kidneys, and glands. How morphogenesis can create architectures very different shapes functions remains elusive. In this review, we compare its regulation lungs kidneys discuss role signaling pathways, mesenchyme, extracellular matrix, cytoskeleton as potential...

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 ...