Branching Out

Science's STKE  17 Oct 2006:
Vol. 2006, Issue 357, pp. tw360
DOI: 10.1126/stke.3572006tw360

At puberty, the female mammary gland is transformed from a simple epithelial tubule into an elaborate ductal tree. Underlying this global change in tissue architecture are changes in the behavior of individual cells. Certain cells within the tubules are instructed to branch, whereas their neighbors, only a few cell diameters away, are not. Using a micropatterning approach to engineer mouse mammary epithelial tubules in culture, Nelson et al. show that the position of branching depends on the initial tubule geometry and is determined by a local minimum in the concentration gradient of autocrine inhibitory morphogens, including transforming growth factor-β.

C. M. Nelson, M. M. VanDuijn, J. L. Inman, D. A. Fletcher, M. J. Bissell, Tissue geometry determines sites of mammary branching morphogenesis in organotypic cultures. Science 314, 298-300 (2006). [Abstract] [Full Text]