Brainier Mice

Science's STKE  23 Jul 2002:
Vol. 2002, Issue 142, pp. tw264-TW264
DOI: 10.1126/stke.2002.142.tw264

The normal mouse brain lacks the folds and gyrations that characterize the surface of the human brain. Chenn and Walsh (see the news story by Vogel) now show that expression of a constitutively active variant of β-catenin, a component of cellular adherens junctions, in transgenic mice resulted in lateral expansion of the mouse cerebral cortex. The brain surface buckled and folded to fit into the cranial cavity. Although the sequence of neuronal differentiation appears to be approximately normal, the numbers of cells are much greater and reflect an expanded pool of neural progenitor cells. The extra β-catenin signaling appears to encourage neural precursors to proliferate rather than differentiate.

A. Chenn. C. A. Walsh, Regulation of cerebral cortical size by control of cell cycle exit in neural precursors, Science 297, 365-369 (2002). [Abstract] [Full Text]

G. Vogel, Missized mutants help identify organ tailors, Science 297, 328 (2002). [Summary] [Full Text]