RESUMO
BACKGROUND: Anti-Müllerian hormone (amh) or Müllerian-inhibiting substance (mis) is a member of the transforming growth factor-ß family of hormones. This gene plays a key role in vertebrate male sex-determination by inhibiting the development of the Müllerian ducts, and has been shown to be the master sex-determinant in the Patagonian pejerrey. RESULTS: In the lingcod, Ophiodon elongatus, both males and females share one copy of amh, however we have identified a second duplicate copy that appears solely in the male individuals. We have developed a PCR-based assay targeting the TGF-ß domain of amh that provides a simple method with which to sex lingcod from a small amount of tissue. An analysis across 57 individuals gave a 100% success rate in identifying the phenotypic sex. CONCLUSIONS: We present a simple method to sex lingcod through non-lethal tissue sampling. A third, independent, male-specific duplication of amh in a teleost fish has been identified in the lingcod.