CPD photolyase gene fragments for Monotremata (Prototheria) and Marsupialia (Metatheria): Raw sequence reads. Aplacental Mammalia

CPD photolyase is an important light-dependent DNA repair enzyme and is widely conserved among bacteria, archaea and eukaryotes (including plants, insects, vertebrates). The taxonomic distribution among mammals is poorly known and understood. No orthologs have been found in placental mammals up till the moment of writing (8 July 2016). In contrast, orthologs for CPD photolyase have been described for two marsupial mammals.We developed primers to target the conserved photoreactive and catalytic domain of the CPD photolyase protein to test the genomes of monotreme (n=3), marsupial (n=9) and placental (n=8) species for an ortholog. Our primers could target fragments (390-670bp) of a CPD photolyase ortholog in all tested monotreme and marsupial species but not in placentals. This may suggest a functional loss of this effective light-dependent DNA repair enzyme in placentals, possibly as a result of a late Mesozoic nocturnal bottleneck, after the ancestral placentals radiated from the last common ancestor with marsupials and monotremes.