Expression of the receptor tyrosine kinase gene EphB3 during early stages of chick embryo development

The expression pattern of the receptor tyrosine kinase gene EphB3 tvas exam ined during the early stages of chick embryogenesis, and is described in th is report. In the gastrula, EphB3 is expressed in epiblast cells adjacent t o and entering the anterior portion of the primitive streak; expression is extinguished once cells have ingressed. At headfold stages, EphB3 is strong ly transcribed in the floor of the foregut and in anterior lateral endoderm , and is expressed in the subjacent cardiogenic mesoderm. EphB3 is transien tly expressed in the lateral ectoderm, neural tube, and neural crest during these stages. Later neural expression is localized to the mesencephalon. I n the semitic mesoderm, EphB3 is initially expressed in the sclerotome, but later is expressed predominantly in the dermatome. Prominent expression is also detected in the developing heart, liver, posterior ventral limb bud m esenchyme, pharyngeal arches, and head mesenchyme. (C) 2001 Elsevier Scienc e Ireland Ltd. All rights reserved.