Expression of the receptor tyrosine kinase genes, Ror1 and Ror2, during mouse development

In mammals, the Ror-family receptor tyrosine kinases consist of two structu rally related proteins, Ror1 and Ror2, characterized by the extracellular F rizzled-like cysteine-rich domain and membrane proximal kringle domains. As an attempt to gain insights into their roles in mouse development, express ion patterns of Ror1 and Ror2 during early embryogenesis were examined and compared. Interestingly, at early stages, Ror1 and Ror2 exhibit similar exp ression patterns in the developing face, including the frontonasal process and pharyngeal arches, which are derived from cephalic neural crest cells. On the other hand, they exhibit different expression patterns in the develo ping limbs and brain, where the expression of Ror2 was detected broadly com pared with that of Ror1. At a later stage, both gents are expressed in a si milar fashion in the developing heart and lung, yet in a distinct manner in the brain and eye. (C) 2001 Elsevier Science Ireland Ltd. All rights reser ved.