Osr2, a new mouse gene related to Drosophila odd-skipped, exhibits dynamic expression patterns during craniofacial, limb, and kidney development.

We have isolated a new mouse gene, odd-skipped related 2 (Osr2), that encodes a zinc finger containing protein related to Drosophila Odd-skipped. The putative OSR2 protein shares 65% amino acid sequence identity overall and 98% sequence identity in the zinc finger region, respectively, with the previously reported Osr1 gene product. During mouse embryonic development, Osr2 expression is first detected at E9.25, specifically in the mesonephric vesicles. By E10.0, Osr2 expression is also observed in the rostro-lateral mandibular mesenchyme immediately adjacent to the maxillary processes. In the developing limb buds, Osr2 is expressed in a unique mesenchymal domain and the onset of Osr2 expression follows a distinct dorsal to ventral developmental time sequence beginning in the forelimb and then in the hindlimb. Osr2 exhibits a dynamic expression pattern during craniofacial development, in the mandibular and maxillary processes as well as the developing palate. Osr2 is also expressed at sites of epithelial-mesenchymal interactions during tooth and kidney development.