Characterization of duDDX1. A Amino-acid alignment of duDDX1. Alignment was performed using the Clustal X program and edited with DNAMAN. DDX1 sequences are shown for the Cherry valley duck (du), chicken (ch), human (hu), and mouse (mo). Black shading indicates amino acid identity, gray shading indicates similarity (50% threshold). B Prediction of protein domains by the SMART program.