N-cadherin protein distribution in normal embryos and in embryos carrying mutations in the homeobox gene Hoxa-4
Published: 1 June 1997
A I Packer, V A Elwell, J D Parnass, K A Knudsen and D J Wolgemuth
Department of Genetics, The Center for Reproductive Sciences, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
N-cadherin is a calcium-dependent adhesion molecule with a potential role in a variety of morphogenetic events. Although a dynamic pattern of expression in the mouse embryo has been suggested by in situ hybridization analysis, to date there has been no report of N-cadherin protein expression. In this immunohistochemical study we surveyed N-cadherin protein expression in the mid-late gestation mouse embryo utilizing a recently characterized monoclonal antibody. We found N-cadherin expression in a wide array of tissues, including the brain, the eye, various cranial ganglia, the spinal cord, spinal ganglia, somites, vertebral and limb cartilage and perichondria, the developing lung and kidney, the enteric nervous system, and germ cells. These results suggest that N-cadherin protein expression, as in the chick embryo, correlates with the segregation of cells and with organogenesis. As cadherins have been proposed as targets of vertebrate Hox genes, we also examined N-cadherin expression in two lines of Hoxa-4 mutant mice. We did not observe any alterations in N-cadherin expression in either Hoxa-4 null embryos or in transgenic embryos that overexpress Hoxa-4 in the mesenchyme of the gut. However, the partial overlap in expression between Hox genes and N-cadherin, and the likelihood of redundancy in the regulation of target genes, leaves open the possibility that cadherins are direct or indirect targets of Hox genes during mouse embryogenesis.