Morphogenesis of branching tubules in cultures of cloned mammary epithelial cells.

摘要: Morphogenesis (the development of biological form, usually multicellular organisms or their parts) is generally studied in simple like the slime mould Dictyostelium1, for mammals even single tissues mammary epithelium discussed here appear complex. Mammary epithelium, supported by mesenchymal tissue, forms a system branching, tubular ducts. During phases rapid growth these ducts end solid, swollen ‘end-buds’, and when mature globular ‘alveoli’2. The mesenchyme influences morphogenesis may be essential this process3,4. An unknown number cell types are present both mesenchyme. One step towards better-defined ‘model gland’ was taken Yang et al.5, who recently described three-dimensional, tumour-like outgrowths from clumps mouse tumour cells cultured floating ‘collagen gel’6 instead on plastic surface. I now describe behaviour retaining some elements natural morphogenesis, cloned line epithelial thus unequivocal absence mesenchyme—unless can arise epithelium. On collagen gel Rama 25 (derived rat tumour7) could generate three-dimensional structures which, although often disorganized tumour-like, included hollow tubules, sometimes with bulbous ends. Thus all information to specify such organization resided type survived cloning. This raises possibility mammalian which morphogenetic mechanisms, relation differentiation, as readily Dictyostelium.