Phenotypic plasticity, genetic variation, and the origins of novel, complex traits

表型可塑性、遗传变异以及新颖、复杂性状的起源

• 批准号: 2306276
• 负责人: David Pfennig
• 金额: $ 141.96万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-15 至 2027-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2306276&HistoricalAwards=false
• 关键词: Phenotypic; plasticity; genetic; variation; origins

Biologists have long recognized that an organism’s features (its ‘phenotype’) can change depending on its environment, but such ‘phenotypic plasticity’ has traditionally been overlooked in the rush to identify the genes that influence traits. In recent years, many scientists have begun asking if phenotypic plasticity might play an important role in fostering the origins of novel, complex traits. However, this idea assumes that phenotypic plasticity is itself underlain by genetic variation, but few studies have identified the genetic bases of phenotypic plasticity in natural populations, especially in vertebrates. Such data are crucial for clarifying the causes and consequences of plasticity, including its possible role in the origins––and subsequent elaboration––of novel, complex traits. The goals of this research are to identify genetic variation underlying a spectacular form of plasticity among the tadpoles of desert frogs. The PIs will also determine where this genetic variation comes from and what component traits it influences. Overall, this research promises to shed new light on the causes and consequences of phenotypic plasticity, an emerging frontier that unites diverse areas of biology. In doing so, this research will help explain how an organism’s genome interacts with its environment to shape the expression and evolution of complex features. A longstanding problem is understanding how novelty arises. According to the plasticity-led evolution (PLE) hypothesis, novel traits arise when a change in the environment triggers a shift in phenotype via phenotypic plasticity. Yet, little is known about the genes underlying this process. This research will identify loci and genetic variation associated with a novel, complex phenotype that appears to have arisen via PLE. In response to eating meat, Mexican spadefoot toad tadpoles develop into a novel carnivore morph, which previous work suggests has evolved via PLE. For this research, the PIs will rear tadpoles from controlled crosses to identify loci underlying this novel phenotype. With these data, the PIs will determine if––as predicted by their preliminary data––many such loci are involved in metabolism and environmental assessment. The PIs will then rear tadpoles in semi-natural environments that they will alter ecologically to differentiate loci associated with the carnivore phenotype per se from loci associated with adaptive environmental assessment and plasticity. With these data, the PIs will determine if adaptive plasticity and phenotypes resulting from that plasticity are regulated by the same or––as predicted by theory––different loci. Finally, the PIs will sequence individuals from numerous natural populations to clarify the roles of standing genetic variation versus introgressed variation in the evolution of the novel carnivore phenotype. Together, these aims will shed new light onto the genetic architecture of plasticity and thereby help illuminate the genetic mechanisms that propel PLE.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

生物学家很早就认识到，生物体的特征（其“表型”）可以根据其环境而变化，但这种“表型可塑性”传统上在急于识别影响性状的基因的过程中被忽视。近年来，许多科学家已经开始这样做。询问表型可塑性是否可能在培育新颖、复杂性状的起源中发挥重要作用。然而，这种想法假设表型可塑性本身是由遗传变异决定的，但很少有研究确定表型可塑性的遗传基础。这些数据对于阐明可塑性的原因和后果至关重要，包括其在新颖、复杂特征的起源以及随后的阐述中的可能作用。沙漠蛙蝌蚪具有惊人的可塑性的遗传变异也将决定这种遗传变异的来源以及它影响的组成特征。总的来说，这项研究有望为解释这种现象的原因和后果提供新的线索。表型可塑性是一个将生物学不同领域结合起来的新兴前沿，这项研究将有助于解释生物体的基因组如何与其环境相互作用以塑造复杂特征的表达和进化。根据可塑性主导的进化（PLE）假说，当环境的变化通过表型可塑性引发表型转变时，就会出现新的特征，然而，我们对这一过程背后的基因知之甚少。与一种新的、复杂的表型相关的变异似乎是通过 PLE 产生的。为了响应吃肉，墨西哥铲足蟾蜍发展成一种新的食肉动物形态，之前的研究表明这种变异是通过 PLE 进化而来的。利用这些数据，PI 将确定是否有许多此类基因座参与新陈代谢和环境评估，正如他们的初步数据所预测的那样。然后，PI 将在半自然环境中饲养蝌蚪，并对其进行生态改变，以区分与食肉动物表型本身相关的基因座和与适应性环境评估和可塑性相关的基因座，利用这些数据，PI 将确定是否会产生适应性可塑性和表型。最后，PI 将对来自众多自然群体的个体进行测序，以阐明长期遗传变异与渐渗变异的作用。总之，这些目标将为可塑性的遗传结构提供新的视角，从而有助于阐明推动 PLE 的遗传机制。该奖项的法定使命，并通过使用基金会的评估被认为值得支持。智力价值和更广泛的影响审查标准。