Costa Mariellen C, Oliveira Paulo R R, Davanço Paulo V, Camargo Crisley de, Laganaro Natasha M, Azeredo Roberto A, Simpson James, Silveira Luis F, Francisco Mercival R
Programa de Pós Graduação em Ecologia e Recursos Naturais, Universidade Federal de São Carlos, Rod. Washington Luís, CEP, São Carlos, SP, Brazil.
Programa de Pós Graduação em Diversidade Biológica e Conservação, Universidade Federal de São Carlos, campus de Sorocaba, Rod. João Leme dos Santos, CEP, Sorocaba, SP, Brazil.
PLoS One. 2017 Jan 5;12(1):e0169636. doi: 10.1371/journal.pone.0169636. eCollection 2017.
The conservation of many endangered taxa relies on hybrid identification, and when hybrids become morphologically indistinguishable from the parental species, the use of molecular markers can assign individual admixture levels. Here, we present the puzzling case of the extinct in the wild Alagoas Curassow (Pauxi mitu), whose captive population descends from only three individuals. Hybridization with the Razor-billed Curassow (P. tuberosa) began more than eight generations ago, and admixture uncertainty affects the whole population. We applied an analysis framework that combined morphological diagnostic traits, Bayesian clustering analyses using 14 microsatellite loci, and mtDNA haplotypes to assess the ancestry of all individuals that were alive from 2008 to 2012. Simulated data revealed that our microsatellites could accurately assign an individual a hybrid origin until the second backcross generation, which permitted us to identify a pure group among the older, but still reproductive animals. No wild species has ever survived such a severe bottleneck, followed by hybridization, and studying the recovery capability of the selected pure Alagoas Curassow group might provide valuable insights into biological conservation theory.
许多濒危分类单元的保护依赖于杂种鉴定，当杂种在形态上与亲本物种无法区分时，使用分子标记可以确定个体的混合程度。在此，我们呈现了野生已灭绝的阿拉戈斯凤冠雉（Pauxi mitu）这一令人困惑的案例，其圈养种群仅源自三只个体。与刀嘴凤冠雉（P. tuberosa）的杂交始于八代多以前，混合情况的不确定性影响着整个种群。我们应用了一个分析框架，该框架结合形态诊断特征、使用14个微卫星位点的贝叶斯聚类分析以及线粒体DNA单倍型，来评估2008年至2012年间存活的所有个体的祖先。模拟数据显示，我们的微卫星能够准确地将个体鉴定为杂种起源，直至第二代回交，这使我们能够在较年长但仍具繁殖能力的动物中识别出一个纯合群体。从未有野生物种在经历如此严重的瓶颈效应后，还能接着发生杂交，而研究选定的纯合阿拉戈斯凤冠雉群体的恢复能力，可能会为生物保护理论提供有价值的见解。
