Lung airway morphogenesis is simulated in a simplified diffusing environment that simulates the mesenchyme to explore the role of morphogens in airway architecture development. Simple rules govern local branching morphogenesis. Morphogen gradients are modeled by four pairs of sources and their diffusion through the mesenchyme. Sensitivity to lobar architecture and mesenchymal morphogen are expl...

The otocyst is the epithelial anlage of the membranous labyrinth which interacts with surrounding cephalic mesenchyme to form an otic capsule. A series of in vitro studies was performed to gain a better understanding of the epithelial-mesenchymal interactions involved in this process. Parallel series of otocyst/mesenchyme (O/M) and isolated periotic mesenchyme (M) explants provided morphologica...

Electroporation is an efficient method of delivering DNA and other charged macromolecules into tissues at precise time points and in precise locations. For example, electroporation has been used with great success to study neural and retinal development in Xenopus, chicken and mouse (1-10). However, it is important to note that in all of these studies, investigators were not targeting soft tiss...

Chick and mouse embryonic lung mesenchyme were incubated in vitro with an equimolar mixture of (12)C- and (15)N-labeled adenosine, guanosine, cytidine, and uridine, and trace amounts of the four tritiated ribonucleosides. This permits an unambiguous method for detecting transfer of macromolecular RNA from such a pre-incubated mesenchyme to responding lung epithelium across a Millipore filter, a...

Members of the T-box (tbx) gene family encode developmentally regulated transcription factors, several of which are implicated in human hereditary diseases. We have cloned the paralogous genes tbx15 and tbx18 in zebrafish and have characterised their expression in detail. tbx15 is expressed in paraxial head mesenchyme and its derivatives, the extraocular and jaw musculature and the posterior ne...

The developing pancreatic epithelium gives rise to all endocrine and exocrine cells of the mature organ. During organogenesis, the epithelial cells receive essential signals from the overlying mesenchyme. Previous studies, focusing on ex vivo tissue explants or complete knockout mice, have identified an important role for the mesenchyme in regulating the expansion of progenitor cells in the ear...

Development of the metanephric kidney requires the concerted interaction of two tissues, the epithelium of the ureteric duct and the metanephric mesenchyme. Signals from the ureter induce the metanephric mesenchyme to condense and proliferate around the ureter tip, reciprocal signals from the mesenchyme induce the ureter tip to grow and to branch. Wnt genes encode secreted glycoproteins, which ...

Members of the Bone morphogenetic protein (BMP) family have been shown to be important signaling molecules throughout mouse development. Accordingly, many BMPs are also expressed during organogenesis of the metanephric kidney. However, only BMP7 has been shown to be absolutely required for proper formation of the kidney, thus the majority of information known involves this family member. BMP7 i...