Heneberg Petr, Dolinay Matej, Matušík Hynek, Pfeiffer Thomas, Nachtigall Winfried, Bizos Jiří, Šimčíková Daniela, Literák Ivan
Charles University in Prague, Third Faculty of Medicine, Prague, Czech Republic.
Masaryk University, Faculty of Science, Department of Botany and Zoology, Brno, Czech Republic.
PLoS One. 2016 Jul 27;11(7):e0159202. doi: 10.1371/journal.pone.0159202. eCollection 2016.
Among Accipitriformes sensu stricto, only a few species have been reported to form hybrid zones; these include the red kite Milvus milvus and black kite Milvus migrans migrans. M. milvus is endemic to the western Palearctic and has an estimated total population of 20-24,000 breeding pairs. The species was in decline until the 1970s due to persecution and has declined again since the 1990s due to ingestion of rodenticide-treated baits, illegal poisoning and changes in agricultural practices, particularly in its core range. Whereas F1 M. milvus × M. migr. migrans hybrid offspring have been found, F2 and F3 hybrids have only rarely been reported, with low nesting success rates of F1 hybrids and partial hybrid sterility likely playing a role. Here, we analyzed the mitochondrial (CO1 and CytB) and nuclear (Myc) DNA loci of 184 M. milvus, 124 M. migr. migrans and 3 F1 hybrid individuals collected across central Europe. In agreement with previous studies, we found low heterozygosity in M. milvus regardless of locus. We found that populations of both examined species were characterized by a high gene flow within populations, with all of the major haplotypes distributed across the entire examined area. Few haplotypes displayed statistically significant aggregation in one region over another. We did not find mitochondrial DNA of one species in individuals with the plumage of the other species, except in F1 hybrids, which agrees with Haldane´s Rule. It remains to be investigated by genomic methods whether occasional gene flow occurs through the paternal line, as the examined Myc gene displayed only marginal divergence between M. milvus and M. migr. migrans. The central European population of M. milvus is clearly subject to free intraspecific gene flow, which has direct implications when considering the origin of individuals in M. milvus re-introduction programs.
在狭义的鹰形目鸟类中，仅有少数物种被报道形成杂交区；其中包括红鸢（Milvus milvus）和黑鸢指名亚种（Milvus migrans migrans）。红鸢是古北界西部的特有物种，估计繁殖对总数为20000 - 24000对。该物种在20世纪70年代前因受迫害而数量下降，自20世纪90年代以来，又因摄入含灭鼠剂的诱饵、非法投毒以及农业 practices 的变化，尤其是在其核心分布区，数量再次下降。虽然已发现红鸢与黑鸢指名亚种的F1杂交后代，但F2和F3杂交种很少被报道，F1杂交种筑巢成功率低以及部分杂交不育可能起到了作用。在此，我们分析了从欧洲中部收集的184只红鸢、124只黑鸢指名亚种和3只F1杂交个体的线粒体（CO1和CytB）和核（Myc）DNA位点。与先前的研究一致，我们发现红鸢无论在哪个位点杂合度都很低。我们发现，所研究的两个物种的种群都具有种群内基因流高的特征，所有主要单倍型分布在整个研究区域。很少有单倍型在一个区域比另一个区域表现出统计学上显著的聚集。除了F1杂交种外，我们在具有另一个物种羽色的个体中未发现一个物种的线粒体DNA，这与霍尔丹法则相符。由于所检测的Myc基因在红鸢和黑鸢指名亚种之间仅表现出微小差异，通过基因组方法研究是否偶尔会通过父系发生基因流仍有待进行。欧洲中部的红鸢种群显然存在自由的种内基因流，这在考虑红鸢重新引入计划中个体的来源时具有直接影响。
