Forkhead Foxe3 maps to the dysgenetic lens locus and is critical in lens development and differentiation

Here we report the isolation of a novel forkhead gene, Foxe3, that plays an important role in lens formation. During development Foxe3 is expressed in all undifferentiated lens tissues, and is turned off upon fiber cell diffe rentiation. Foxe3 maps to a chromosomal region containing the dysgenetic le ns (dyl) mutation. Mice homozygous for dyl display several defects in lens development, dyl mice also show altered patterns of crystallin expression s uggesting a dysregulation of lens differentiation. We have identified mutat ions in Foxe3 that cosegregate with the dyl phenotype and are a likely caus e of the mutant phenotype, Head ectoderm expression of Foxe3 is absent in R x-/- and Small eye embryos indicating that Rx and Pax6 activity are necessa ry for Foxe3 expression. (C) 2000 Wiley-Liss, Inc.