DUXB and CPHX loci in mouse and human. (A) Mouse DUXB-like (Duxbl, orange arrows) and Cphx (red arrows), together with a non-homeobox gene Plac9 (green arrows), have been duplicated giving three copies each at chromosome 14A3. (B) Human Cphx-related homeobox loci flank a DUXBL pseudogene and the DUXB gene on chromosomes 10 and 16 respectively, although the loci on chromosome 10 are disrupted (ragged boxes). Anxa11 (blue arrows) is not a homeobox genes. (C) Amino acid alignments; dots represent identical amino acids, dashes deletons/insertions and red characters conservative substitutions. Hs, Homo sapiens; Mm, Mus musculus.