Molecular basis and evolution of visual mate recognition in Heliconius butterflies

适应不同的生态位可以导致新物种的进化，进化生物学的一个主要目标是确定种群分化背后的遗传变化。相对于形态特征，在自然界中观察到的行为差异的遗传学尚未得到很好的表征。对于造成生殖隔离的行为尤其如此。然而，这些行为，如选择性配偶偏好，在种群分化过程中迅速进化，在新物种的进化过程中非常重要。Heliconius蝴蝶是为数不多的几个系统之一，在这些系统中，有可能在其生态背景下完全剖析配偶识别行为的遗传学和进化史。这一新热带区属以其明亮的警告模式而闻名，并且在适应和物种形成方面得到了特别好的研究。远亲物种经常使用相同的警告模式，由于模仿的选择。然而，密切相关的物种可以看起来非常不同，非模仿杂交，这是不被认为是令人厌恶的，遭受增加捕食。颜色图案的变化也导致行为隔离，因为雄性对自己的翅膀图案的偏好超过了密切相关的物种。然而，尽管我们现在已经非常详细地了解了警告模式的遗传学，但我们在分子水平上对相应行为的理解仍然有限。我的研究目的是确定在Heliconius蝴蝶视觉配偶识别的因果基因。我将首先开发新的方法来有效和准确地量化视觉吸引力。通过将现代分子技术与大型绘图人群的准确行为数据相结合，我将确定视觉吸引力差异的狭窄基因组区域。这些分析将在同域生态分歧物种之间进行，然后在不接触的物种之间进行。这将检验物种形成研究的一个关键假设，即控制行为和生态特征的基因座在基因组中聚集，这些特征导致保持接触的种群之间的生殖隔离。识别多个物种对中的候选区域也将有助于基因组分析，以进一步确定视觉吸引力的遗传基础。我将联合收割机这些分析与表达研究相结合，最终目标是为功能实验提供候选人。这项工作将为物种形成提供新的见解，这是进化和生物多样性的基本过程，但也对我们理解生态相关行为的遗传学具有更广泛的影响。

Adaptation to different ecological niches can result in the evolution of new species, and a major goal of evolutionary biology is to identify the genetic changes underlying population divergence. Relative to morphological traits, the genetics of behavioural differences observed in nature have not been well characterized. This is especially true for behaviours that contribute to reproductive isolation. However, these behaviours, such as assortative mate preferences, are known to evolve rapidly during population divergence and are important during the evolution of new species. The Heliconius butterflies are one of only a few systems in which it will be possible to fully dissect the genetics and evolutionary history of mate recognition behaviours within their ecological context. This Neotropical genus is well known for its bright warning patterns, and has been especially well studied with respect to adaptation and speciation. Distantly related species often use the same warning pattern due to selection for mimicry. However, closely related species can look very different and non-mimetic hybrids, which are not recognized as distasteful, suffer increased predation. Shifts in colour pattern also result in behavioural isolation as males show a preference for their own wing pattern over that of closely related species. However, while the genetics of warning pattern are now known in fantastic detail, our understanding of the corresponding behaviours at the molecular level remains limited. My research aims to identify the causal genes underlying visual mate recognition in Heliconius butterflies. I will first develop novel methods to efficiently and accurately quantify visual attraction. By combining modern molecular techniques with accurate behavioural data for a large mapping population, I will identify narrow genomic regions underlying differences in visual attraction. These analyses will be conducted between ecologically divergent species that are sympatric, and then between species which are not in contact. This will test a key hypothesis of speciation research that loci controlling behavioural and ecological traits that cause reproductive isolation between populations that remain in contact are clustered in the genome. Identifying the candidate regions in multiple species pairs will also facilitate genomic analyses to further key in on the genetic basis of visual attraction. I will combine these analyses with expression studies with the ultimate goal of providing candidates for functional experiments. This work will offer new insights into speciation, a process fundamental to evolution and biodiversity, but also has wider implications for our understanding of the genetics of ecologically relevant behaviours.