Neural divergence and hybrid disruption between ecologically isolated Heliconius butterflies
Neural divergence and hybrid disruption between ecologically isolated Heliconius butterflies
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生态隔离的 Heliconius 蝴蝶之间的神经分歧和杂交破坏
DOI：
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发表时间：
2020
影响因子：
11.1
通讯作者：
R. Merrill
中科院分区：
文献类型：
--
作者：
S. Montgomery;Matteo Rossi;W. McMillan;R. Merrill
意义虽然以前的研究强调了生态变异在驱动大脑形态分化中的重要性，但这些变化是在生态转变之后积累起来的，还是在促进生态转变方面发挥了重要作用尚不清楚。我们发现，与微生境划分相关的分歧选择推动了赫利柯斯蝴蝶姐妹支系之间在大脑组成和神经基因表达方面的可遗传差异。神经解剖学上的分歧仅限于视觉结构，反映了对不同感觉区位的适应。我们通过证明杂交后代具有中间性状，并提出证据表明，具有适应性表达差异模式的基因更有可能出现在基因组中抵抗种间基因流动的区域，从而展示了不同的神经特征如何成为基因流动的障碍。物种形成过程中行为进化的重要性已经得到了很好的证实，但我们对这一点如何在感觉和神经系统中表现出来知之甚少。一些研究已经将特定的神经变化与与物种形成相关的寄主或配偶偏好的差异联系起来。然而，大脑对当地环境条件的适应程度，以及这是否会导致生态上存在分歧的近亲之间的生殖隔离，目前尚不清楚。在这里，我们研究了密切相关但生态上不同的赫利柯斯蝴蝶在大脑形态和神经基因表达方面的差异。尽管正在进行基因流动，Melpomene-Cydno复合体中的共域物种对在开阔到封闭的森林和递减的光照强度的梯度上一直是分开的。通过为107只蝴蝶生成定量的神经解剖学数据，我们表明，梅尔波梅氏和苏云金蝶分支在其地理范围内的大脑形态发生了实质性的变化，视觉系统中聚集了不同的结构。这些神经解剖学上的差异反映在神经基因表达的广泛差异上。神经形态和基因表达的差异都是可遗传的，超过了预期的中性分歧率，并导致了第一代杂交后代的中间性状。差异选择的强烈证据表明，在每个亲本的微生境中，杂交种对不同的选择最优具有局部适应性，这表明杂交种的中间性状与任何一种条件都不匹配。因此，神经特征可能有助于基因流动的一致障碍，从而有助于促进物种形成。
Significance Although previous studies highlight the importance of ecological variation in driving divergence in brain morphology, whether these changes accumulate after ecological transitions or play a significant role in facilitating them is unclear. We show that divergent selection associated with microhabitat partitioning drove heritable divergence in brain composition and neural gene expression between sister clades of Heliconius butterflies. Neuroanatomical divergence is restricted to visual structures and reflect adaptations to contrasting sensory niches. We show how divergent neural traits can act as barriers to gene flow by demonstrating that hybrids have intermediate traits and by presenting evidence that genes with adaptive patterns of expression divergence are more likely to occur in regions of the genome that are resistant to interspecific gene flow. The importance of behavioral evolution during speciation is well established, but we know little about how this is manifest in sensory and neural systems. A handful of studies have linked specific neural changes to divergence in host or mate preferences associated with speciation. However, the degree to which brains are adapted to local environmental conditions, and whether this contributes to reproductive isolation between close relatives that have diverged in ecology, remains unknown. Here, we examine divergence in brain morphology and neural gene expression between closely related, but ecologically distinct, Heliconius butterflies. Despite ongoing gene flow, sympatric species pairs within the melpomene–cydno complex are consistently separated across a gradient of open to closed forest and decreasing light intensity. By generating quantitative neuroanatomical data for 107 butterflies, we show that Heliconius melpomene and Heliconius cydno clades have substantial shifts in brain morphology across their geographic range, with divergent structures clustered in the visual system. These neuroanatomical differences are mirrored by extensive divergence in neural gene expression. Differences in both neural morphology and gene expression are heritable, exceed expected rates of neutral divergence, and result in intermediate traits in first-generation hybrid offspring. Strong evidence of divergent selection implies local adaptation to distinct selective optima in each parental microhabitat, suggesting the intermediate traits of hybrids are poorly matched to either condition. Neural traits may therefore contribute to coincident barriers to gene flow, thereby helping to facilitate speciation.
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影响因子：
3.3
作者：
Catalan, Ana;Briscoe, Adriana D.;Hohna, Sebastian
通讯作者：
Hohna, Sebastian
DOI：
10.1098/rspb.2016.2101
发表时间：
2016-12-28
期刊：
Proceedings. Biological sciences
影响因子：
--
作者：
Tait C;Batra S;Ramaswamy SS;Feder JL;Olsson SB
通讯作者：
Olsson SB
影响因子：
2.2
作者：
Keagy J;Braithwaite VA;Boughman JW;Handling editor: Rudiger Riesch
通讯作者：
Handling editor: Rudiger Riesch
神经结构与视觉表现的相关性：双翅目视觉系统的系统发育保守和变异。
DOI：
--
发表时间：
1997
期刊：
The Journal of comparative neurology.
影响因子：
--
作者：
Buschbeck,EK;Strausfeld,NJ
通讯作者：
Strausfeld,NJ