RESUMEN
mPem, a homeobox gene, is expressed in a time and stage specific manner during murine ontogeny. Pem transcripts are abundant in 7- and 8-day mouse embryos, but decrease precipitously thereafter. On Day 9 they become abundant in placenta and yolk sac, persisting there until parturition. Although Pem transcripts are not detectable in most of adult tissues, they are present in reproductive system such as testis, epididymis and ovary. This indicates a important role for Pem during embryogenesis and reproductive development. To study the function of mPem protein, we used a GAL4 based yeast two-hybrid assay to screen a 7-day mouse embryo library with full-length of mPem. 3 proteins were found interacting with mPem protein. One of theses is Mdfic. We confirmed the interaction between mPem and Mdfic in yeast and in vitro. Mdfic, MyoD family inhibitor domain containing, encodes the myoD family inhibitor domain (I-mfa domain). The interaction between mPem and Mdfic suggested they maybe form the transcriptional regulator complex to regulate embryo differentiation.