BACKGROUND Within the Culex pipiens mosquito complex, there are six contemporarily recognized taxa: Cx. quinquefasciatus, Cx. pipiens f. pipiens, Cx. pipiens f. molestus, Cx. pipiens pallens, Cx. australicus and Cx. globocoxitus. Many phylogenetic aspects within this complex have eluded resolution, such as the relationship of the two Australian endemic taxa to the other four members, as well as the evolutionary origins and taxonomic status of Cx. pipiens pallens and Cx. pipiens f. molestus. Ultimately, insights into lineage relationships within the complex will facilitate a better understanding of differential disease transmission by these mosquitoes. To this end, we have combined publicly available data with our own sequencing efforts to examine these questions. RESULTS We found that the two Australian endemic complex members, Cx. australicus and Cx. globocoxitus, comprise a monophyletic group, are genetically distinct, and are most closely related to the cosmopolitan Cx. quinquefasciatus. Our results also show that Cx. pipiens pallens is genetically distinct, but may have arisen from past hybridization. Lastly, we observed complicated patterns of genetic differentiation within and between Cx. pipiens f. pipiens and Cx. pipiens f. molestus. CONCLUSIONS Two Australian endemic Culex taxa, Cx. australicus and Cx. globocoxitus, belong within the Cx. pipiens complex, but have a relatively older evolutionary origin. They likely diverged from Cx. quinquefasciatus after its colonization of Australia. The taxon Cx. pipiens pallens is a distinct evolutionary entity that likely arose from past hybridization between Cx. quinquefasciatus and Cx. pipiens f. pipiens/Cx. pipiens f. molestus. Our results do not suggest it derives from ongoing hybridization. Finally, genetic differentiation within the Cx. pipiens f. pipiens and Cx. pipiens f. molestus samples suggests that they collectively form two separate geographic clades, one in North America and one in Europe and the Mediterranean. This may indicate that the Cx. pipiens f. molestus form has two distinct origins, arising from Cx. pipiens f. pipiens in each region. However, ongoing genetic exchange within and between these taxa have obscured their evolutionary histories, and could also explain the absence of monophyly among our samples. Overall, this work suggests many avenues that warrant further investigation.

中文翻译：

---

对蚊子库蚊复合体内的分类关系和混合进行总体评估。


背景技术在淡色库蚊复合体中，有六种目前公认的类群：Cx。致倦五线虫，Cx。皮皮安斯 f.皮皮安斯，Cx。皮皮安斯 f.摩尔斯图斯，Cx。淡色苍白，Cx。澳大利亚和 Cx。球状颤动。这个复合体中的许多系统发育方面尚未得到解决，例如两个澳大利亚特有类群与其他四个成员的关系，以及 Cx 的进化起源和分类地位。 pipiens pallens 和 Cx。皮皮安斯 f.骚扰者。最终，深入了解该复合体内的谱系关系将有助于更好地了解这些蚊子的差异性疾病传播。为此，我们将公开数据与我们自己的测序工作相结合来研究这些问题。结果我们发现两个澳大利亚地方病复合体成员Cx。澳大利亚和 Cx。 globocoxitus 由单系群组成，在遗传上是不同的，并且与世界性 Cx 关系最密切。致倦五线虫。我们的结果还表明 Cx。 pipiens pallens 在遗传上是不同的，但可能是由过去的杂交产生的。最后，我们观察到 Cx 内部和之间遗传分化的复杂模式。皮皮安斯 f. pipiens 和 Cx。皮皮安斯 f.骚扰者。结论 两个澳大利亚特有库蚊类群，Cx。澳大利亚和 Cx。 globocoxitus，属于Cx。 pipiens 复合体，但具有相对古老的进化起源。他们可能与 Cx 不同。 quinquefasciatus 殖民澳大利亚后。分类单元 Cx。 pipiens pallens 是一个独特的进化实体，可能源自过去 Cx 之间的杂交。 quinquefasciatus 和 Cx。皮皮安斯 f. pipiens/Cx。皮皮安斯 f.骚扰者。我们的结果并不表明它源自正在进行的杂交。 最后，Cx 内的遗传分化。皮皮安斯 f. pipiens 和 Cx。皮皮安斯 f.鼹鼠样本表明，它们共同形成了两个独立的地理分支，一个在北美，一个在欧洲和地中海。这可能表明 Cx.皮皮安斯 f. molestus 形式有两个不同的起源，源自 Cx。皮皮安斯 f.各个地区的pipiens。然而，这些类群内部和之间正在进行的遗传交换掩盖了它们的进化历史，这也可以解释我们的样本中不存在单系性的情况。总的来说，这项工作提出了许多值得进一步研究的途径。