Sequence conservation of an avian centromeric repeated DNA component.

The approximately 190-bp centromeric repeat monomers of the spur-winged lapwing (Vanellus spinosus, Charadriidae), the Chilean flamingo (Phoenicopterus chilensis, Phoenicopteridae), the sarus crane (Grus antigone, Gruidae), parrots (Psittacidae), waterfowl (Anatidae), and the merlin (Falco columbarius, Falconidae) contain elements that are interspecifically highly variable, as well as elements (trinucleotides and higher order oligonucleotides) that are highly conserved in sequence and relative location within the repeat. Such conservation suggests that the centromeric repeats of these avian species have evolved from a common ancestral sequence that may date from very early stages of avian radiation.