Mammalian DUX distribution. Summary of our mammalian DUX catalogue. Presumed functional genes (with intact ORF across all four homeobox exons, first exon may be unidentified) in green. DUX sequences with stop codons or deleted/missing exons in well sequenced regions in red. Putative DUX homologues with unclear functional status (mainly due to gaps in assembly) in yellow. Unless marked with ?, synteny was confirmed with anchor genes. Phylogenetic relationship between species according to references[28, 44].