| Popis: |
During chick wing morphogenesis, reciprocal interactions take place between the apical ectodermal ridge (AER) and the subjacent mesoderm. The AER (a pseudostratified columnar epithelium) induces limb outgrowth, while the limb mesoderm induces the formation of the apical ridge and subsequently maintains both its specialized morphology and its functional properties (reviewed by Fallon, et al., 1983). Although the morphogenetic importance of AER-mesenchymal communication is now well established, the underlying mechanisms involved have not been identified. However, studies in other developing systems have provided good evidence that the extracellular matrix (ECM) is involved in mediating some epithelial-mesenchymal interactions (Bernfield et al., 1984). Furthermore, the ECM is known to control many aspects of cell behaviour in culture, including motility, morphology and differentiation (Trelstad, 1984). Despite this, comparatively few studies have explored the possibility that the ECM also functions in mediating ridgemesenchymal interactions (Tomasek and Brier, 1986). The aim of the present study was to identify specialized features of the ECM at the ridge/mesenchyme interface which may function in the maintenance of ridge structure, or the promotion of wing outgrowth. |
