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.

尽管性别分配对于研究动物的生物学和生态学至关重要，但在Xenarthra中，尚无用于鉴定性别的标准化方法。在这里，我们评估了两个核片段[锌指（〜400 bp）和性别决定区Y（〜180 bp）基因]对七个Xenarthra物种进行性别鉴定的潜力。首先，我们扩增并测序了锌指基因的两个同源片段（Zfx和Zfy）代表Xenarthra的系统发育多样性。由于在进化上不密切相关的三个物种的同源区段中不存在多态性，我们使用上述基因应用了多重聚合酶链反应（多重PCR）方法。最后，我们使用了三种最死路的Xenarthra（Myrmecophaga tridactyla，Tamandua tetradactyla和Euphractus sexcinctus）的组织样本进行了案例研究），以评估我们的多重PCR方法在这些失去其形态特征的个体中进行性别鉴定的能力。该方法被证明对不同类型的样品中的分子性别鉴定是有效的，对于使用劣质DNA的研究可能特别有用。我们讨论了每种方法在遗传和生态学研究中的适用性。