Expression of the novel Snai-related zinc-ringer transcription factor gene Smuc during mouse development

The Snai-related proteins are zinc-finger transcription factors that play important roles in cell-fate determination. We previously cloned a novel Snai-related gene known as snail-related transcription factor of muscle cells (Smuc) or, more recently, as snail homologue 3 (Snai3). In the present study, we investigated the functional roles of Smuc using in situ hybridization analysis at various stages of mouse development. Smuc was not detected until 12.5 days post-coitus (dpc). Its expression was observed in the skeletal muscles and thymus at 13.5 and 15.5 dpc, respectively, and these remained the major sites of Smuc expression until postnatal day 2. No Smuc expression was observed in the heart, large vessels, lungs, liver, kidney or brain. These results indicate that Smuc might be involved in the morphogenesis of the skeletal muscles and thymus at a relatively late stage of mouse development.