A novel mitochondrial gene order in shorebirds (Scolopacidae, Charadriiformes)

Although the mitochondrial genome in birds has highly conserved features, with protein genes similar to mammals and amphibians, several variations in gene order around the hypervariable control region have been found. Here we report a novel gene arrangement around the control region in shorebirds (Charadriiformes). In ruffs Philomachus pugnax, the mitochondrial genome between cytochrome b and 12SrRNA was over 1.5 kb longer than reported for other Charadriiformes and contained a duplication of the control region together with NADH dehydrogenase subunit 6 (ND6) and the adjacent transfer RNAs: tRNAPro and tRNAGlu. Sequence data from 68 individuals from several stopover and breeding populations show that the duplication is widespread in ruffs. Similar gene re-arrangements have been found independently in unrelated tube-nosed seabirds and spoonbills.