Chen Yanke, An Bei, Liu Naifa
Experiment Center of Biomedical Research School of Medicine, Xi'an Jiaotong University, Xi'an, China.
School of Life Sciences, Lanzhou University, Lanzhou, China.
Integr Zool. 2016 Sep;11(5):403-12. doi: 10.1111/1749-4877.12195.
The rusty-necklaced partridge (Alectoris magna) and the chukar partridge (Alectoris chukar) are the most common gamebirds in northern China. Previous comparisons of mitochondrial DNA (mtDNA) have revealed an introgression phenomenon between 2 species of partridge in the Liupan Mountain region of China. mtDNA is maternally inherited, making it difficult to determine the origin of parental genes. We assessed the genetic variation and gene flow between these 2 species of partridges using 8 microsatellite loci as neutral diagnostic markers in 171 samples from the hybrid zone. Our data revealed an extensive divergence of genetic structure between populations of rusty-necklaced partridges and chukar partridges. In this study, we found that 19 samples had been previously morphologically identified as rusty-necklaced partridge were genetically identified as hybrids through Bayesian analysis using STRUCTURE analysis. These hybrids exhibited a mosaic of alleles that were derived from both parental lineages. However, chukar partridges did not present the genotype of the rusty-necklaced partridge. Thus, our findings demonstrate that the hybridization between the 2 species was the result of asymmetrical introgression, with gene flow occurring only from the chukar partridge to the rusty-necklaced partridge. In addition, we also note the high linkage disequilibrium in populations of the rusty-necklaced partridge. These results indicate that although unidirectional introgression did not reduce genetic diversity of the Alectoris partridges, it affected the balance of gene flow between populations. The data from microsatellite DNA prompted our concern about the genetic integrity of the rusty-necklaced partridge.
环颈山鹧鸪（Alectoris magna）和石鸡（Alectoris chukar）是中国北方最常见的猎禽。先前对线粒体DNA（mtDNA）的比较揭示了中国六盘山地区两种鹧鸪之间的基因渐渗现象。mtDNA是母系遗传的，这使得确定亲本基因的来源变得困难。我们使用8个微卫星位点作为中性诊断标记，对来自杂交区的171个样本进行分析，评估了这两种鹧鸪之间的遗传变异和基因流动。我们的数据揭示了环颈山鹧鸪和石鸡种群之间遗传结构的广泛差异。在本研究中，我们发现通过使用STRUCTURE分析的贝叶斯分析，先前在形态上被鉴定为环颈山鹧鸪的19个样本在基因上被鉴定为杂交种。这些杂交种表现出来自两个亲本谱系的等位基因镶嵌。然而，石鸡并没有呈现环颈山鹧鸪的基因型。因此，我们的研究结果表明，这两个物种之间的杂交是不对称渐渗的结果，基因流动仅从石鸡流向环颈山鹧鸪。此外，我们还注意到环颈山鹧鸪种群中存在高度的连锁不平衡。这些结果表明，尽管单向渐渗并没有降低石鸡属鹧鸪的遗传多样性，但它影响了种群之间基因流动的平衡。微卫星DNA的数据促使我们关注环颈山鹧鸪的遗传完整性。
