Kicking Triturus arntzeni when it’s down: large-scale nuclear genetic data confirm that newts from the type locality are genetically admixed

We collected nuclear DNA data (52 markers) with next-generation sequencing for nine Triturus newt specimens, including the holotype and two of the paratypes of T. arntzeni, from the type locality at Vrtovać in eastern Serbia. We compare these data to a reference set composed of the four crested newt species distributed in eastern Serbia namely T. cristatus, T. dobrogicus, T. ivanbureschi and T. macedonicus to determine to which of these species the newts from the type locality of T. arntzeni should be attributed. The majority of alleles in individuals from Vrtovać is derived from T. macedonicus, but a considerable number of T. ivanbureschi alleles is also present; alleles typical for T. cristatus and T. dobrogicus are found at low frequency. Accordingly, we interpret Vrtovać as a T. macedonicus – T. ivanbureschi hybrid population, albeit not composed of F1 hybrids but of genetically admixed individuals derived through multiple generations of backcrossing. The data support the notion tha...

我们采用下一代测序（next-generation sequencing）技术，从塞尔维亚东部的模式产地弗尔托瓦茨（Vrtovać）处采集了9份嵴螈属（Triturus）蝾螈标本，并针对其获取了含52个分子标记的核DNA（nuclear DNA）数据，标本涵盖T. arntzeni的正模标本（holotype）与2份副模标本（paratype）。我们将该数据集与由分布于塞尔维亚东部的4种嵴螈所构成的参考数据集进行比对，这4种嵴螈分别为T. cristatus、T. dobrogicus、T. ivanbureschi与T. macedonicus，以此明确采自T. arntzeni模式产地的蝾螈应划归至哪一物种。弗尔托瓦茨种群个体中的绝大多数等位基因（allele）均源自T. macedonicus，但同时也存在相当数量的T. ivanbureschi等位基因；而T. cristatus与T. dobrogicus的特征等位基因仅以极低频率出现。据此，我们将弗尔托瓦茨种群认定为T. macedonicus与T. ivanbureschi的杂交种群，该种群并非由子一代杂种（F1 hybrid）构成，而是经过多代回交（backcrossing）形成的混合遗传个体。本研究数据支持如下观点：