Genomic divergence and lack of introgressive hybridization between two 13-year periodical cicadas support life cycle switching in the face of climate change
Genomic divergence and lack of introgressive hybridization between two 13-year periodical cicadas support life cycle switching in the face of climate change
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DOI：
10.1111/mec.13858
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发表时间：
2016-11-01
影响因子：
4.9
通讯作者：
Sota，Teiji
中科院分区：
文献类型：
--
作者：
Koyama，Takuya;Ito，Hiromu;Sota，Teiji
据推测，后更新世气候变化刺激的生活史进化是周期蝉（Magicicada）目前多样性的原因，但生命周期变化的机制一直存在争议。为了了解13年和17年蝉生命周期的分化过程，我们研究了Decim群中两种同时出现的近亲13年周期蝉物种Magicicada tredecim和M之间的遗传关系。 新特里西姆。后者被假设为混合起源或通过发育可塑性从 17 年周期转变而来。使用所有 Decim 物种和巢群的限制性位点相关 DNA 序列进行的系统发育分析表明，13 年 M. tredecimlineage 在基因组上与 17-yearMagicicada septendecim 不同，但 13-yearM. 新特里德西米斯不是。我们检测到 M 之间没有显着的基因渗入。 特雷德西曼德 M. 新特雷西姆/M。 七十进制反驳了 M 的假设。 neotredecimare 之间的杂交产物。 特雷德西曼德 M. 七十进制。此外，我们发现，在两个 13 年物种之间的接触区中，渐渗杂交非常罕见或不存在，单核苷酸多态性、线粒体谱系同一性、头部宽度和腹部腹板颜色表型的分离模式证明了这一点。我们的研究表明，这两个 13 年生的 Decim 物种具有独立的起源，并且几乎完全生殖隔离。将我们的数据与对部分群体中偶尔生命周期变化的不断观察（例如，17 年物种的出现速度加快 4 年）相结合，我们认为发育可塑性在魔法蝉生命周期进化中发挥着关键作用。
Life history evolution spurred by post‐Pleistocene climatic change is hypothesized to be responsible for the present diversity in periodical cicadas (Magicicada), but the mechanism of life cycle change has been controversial. To understand the divergence process of 13‐year and 17‐year cicada life cycles, we studied genetic relationships between two synchronously emerging, parapatric 13‐year periodical cicada species in the Decim group,Magicicada tredecimandM. neotredecim. The latter was hypothesized to be of hybrid origin or to have switched from a 17‐year cycle via developmental plasticity. Phylogenetic analysis using restriction‐site‐associated DNA sequences for all Decim species and broods revealed that the 13‐yearM. tredecimlineage is genomically distinct from 17‐yearMagicicada septendecimbut that 13‐yearM. neotredecimis not. We detected no significant introgression betweenM. tredecimandM. neotredecim/M. septendecimthus refuting the hypothesis thatM. neotredecimare products of hybridization betweenM. tredecimandM. septendecim. Further, we found that introgressive hybridization is very rare or absent in the contact zone between the two 13‐year species evidenced by segregation patterns in single nucleotide polymorphisms, mitochondrial lineage identity and head width and abdominal sternite colour phenotypes. Our study demonstrates that the two 13‐year Decim species are of independent origin and nearly completely reproductively isolated. Combining our data with increasing observations of occasional life cycle change in part of a cohort (e.g. 4‐year acceleration of emergence in 17‐year species), we suggest a pivotal role for developmental plasticity inMagicicadalife cycle evolution.