Molecular sex determination in primates including non-invasive umbilical cord samples from neonates of three endangered species

BACKGROUND: Molecular sex determination is a valuable tool for an effective population management in captive bred endangered species. The molecular approaches are particularly valuable in species with limited sexual dimorphism. Moreover, the utilization of accessible non-invasive samples from newborn animals enables early sex determination beneficial for the animal population management and planning. METHODS AND RESULTS: A rapid molecular sex determination method using PCR with specific primers targeting the male-specific SRY locus and the control c-myc gene present in both sexes was developed. The method was validated using DNA samples from blood of adult males and females of Sumatran orangutan (Pongo abelii), western lowland gorilla (Gorilla gorilla gorilla), and silvery gibbon (Hylobates moloch). Then we applied the method to non-invasive samples from four newborns: two Sumatran orangutans, one western lowland gorilla, and one silvery gibbon. DNA of the newborns was isolated from umbilical cord material obtained post partum and/or hair. Additionally to the above mentioned species, the method was also successfully validated in adult males and females of chimpanzee (Pan troglodytes), pig-tailed macaque (Macaca nemestrina), Campbell's monkey (Cercopithecus campbelli), mantled guereza (Colobus guereza), Geoffroy's spider monkey (Ateles geoffroyi), and black-and-white ruffed lemur (Varecia variegata). CONCLUSIONS: We demonstrated that the umbilical cord material can be used for molecular sex determination in newborns and that the c-myc gene can serve as a control gene in molecular sex determination, providing an alternative to other commonly used methods.