DmX gene

The DmX gene (Drosophila melanogaster X-gene) is an extremely large WD-repeat-containing protein coding gene, which is found in all eukaryotes sequenced so far. Loss of functions mutations are lethal in Drosophila melanogaster during first larval instar. In human and mouse, probably in all mammalians, there are two copies of the DmX present, called DMXL1 and DMXL2. The ubiquitous existence of this gene in all higher organisms and the fact that the fruitfly cannot live without a functional copy of this gene indicates that the DmX coded protein is indispensable for life. The DmX gene codes for one of the largest non internally repetitive polypeptide chain known.