Development of a CAPS (cleaved amplified polymorphics sequence) assay for sex identification of the emu (Dromaius novaehollandiae)

Polymerase chain reaction (PCR) based procedures that have been used to identify the sex of most birds cannot be used in ratites. This paper describes the identification of a female (W‐chromosome) specific randomly amplified polymorphic (RAPD) 1.3 kb DNA fragment (ESEXW) in the emu (Dromaius novaehollandiae). Southern blot experiments and sequence analysis revealed that a related (96% similarity) sequence exists on the emu Z‐chromosome (ESEXZ). The sequences of ESEXW and ESEXZ have been used for the development of a two‐primer CAPS (cleaved amplified polymorphic sequence) assay for reliable sex identification of the emu.