Complete homology in metallothionein from two genera of ducks and their hybrids

Metallothionein purified from two genera of domesticated duck, Anas platyrhnchos and Cairina muschata, and their hybrid were analyzed and shown to consist of one identical amino acid sequence. Since most vertebrates carry two or more isospecies of this inducible, thiol rich, metal sequestering protein, this finding suggests that duck metallothionein is evolutionary primitive.