LAUSR

Although sex assignment is essential to study biology and ecology of an animal, in Xenarthra there is still no standardized assay for genetic sex identification. Here, we evaluate the potential of two nuclear fragments [Zinc finger (~ 400 bp) and Sex-determination region Y (~ 180 bp) genes] for sex identification of seven Xenarthra species. First, we amplified and sequenced both homologous segments of Zinc finger gene ( Zfx and Zfy ) in species from each suborder that represents the phylogenetic diversity in Xenarthra. Because of the absence of polymorphisms in the homologous segments in three species phylogenetically not closely related, we applied a multiplex polymerase chain reaction (multiplex PCR) approach using the genes described above. Finally, we performed a case study using tissue samples from the three most road-killed species of Xenarthra ( Myrmecophaga tridactyla, Tamandua tetradactyla and Euphractus sexcinctus ) to evaluate our multiplex PCR approach for sex identification in these individuals that have lost their morphological characteristics. The method proved to be efficient for molecular sex identification in the different types of samples and may be especially useful for studies using poor quality DNA. We discussed each approach with an applicability in genetic and ecological studies.