Dapper (Dpr) proteins are context-dependent regulators of Wnt and Tgf beta signaling. However, although inroads into their molecular properties have been made, their expression and biological function are not understood. Searching for avian Dpr genes, we found that the chicken harbors a Dpr1 and a Dpr2 paralogue only. The genes are expressed in distinct patterns at gastrulation, neurulation, and organogenesis stages of development with key expression domains being the posterior primitive streak, anterior node and notochord, presomitic mesoderm (segmental plate), lateral and cardiac mesoderm, limb mesenchyme, and neurogenic placodes for Dpr1, and anterior primitive streak, node, epithelial somites, embryonic muscle stem cells, oral ectoderm and endoderm, neural crest cells, limb ectoderm, and lung buds for Dpr2. Expression overlaps in a few tissues; however, in several tissues, expression is complementary. Developmental Dynamics 238:1166-1178, 2009. (C) 2009 Wiley-Liss, Inc.