Data from: Environmental and genetic control of brain and song structure in the zebra finch

Birdsong is a classic example of a learned trait with cultural inheritance, with selection acting on trait expression. To understand how song responds to selection, it is vital to determine the extent to which variation in song learning and neuroanatomy is attributable to genetic variation, environmental conditions, or their interactions. Using a partial cross fostering design with an experimental stressor, we quantified the heritability of song structure and key brain nuclei in the song control system of the zebra finch and the genotype-by-environment (G × E) interactions. Neuroanatomy and song structure both showed low levels of heritability and are unlikely to be under selection as indicators of genetic quality. HVC, in particular, was almost entirely under environmental control. G × E interaction was important for brain development and may provide a mechanism by which additive genetic variation is maintained, which in turn may promote sexual selection through female choice. Our study suggests that selection may act on the genes determining vocal learning, rather than directly on the underlying neuroanatomy, and emphasizes the fundamental importance of environmental conditions for vocal learning and neural development in songbirds.

鸟类鸣唱是兼具文化传承的习得性状的经典范例，选择作用于该性状的表达。为理解鸣唱如何响应选择，明确鸣唱学习与神经解剖结构的变异在多大程度上可归因于遗传变异、环境条件，抑或二者的交互作用，至关重要。本研究采用搭载实验性应激源的部分交叉抚养实验设计，对斑胸草雀鸣唱控制系统内的鸣唱结构与关键脑核团的遗传力，以及基因型-环境互作（G×E）进行了量化分析。结果显示，神经解剖结构与鸣唱结构均呈现较低的遗传力水平，二者均不太可能作为遗传质量的指示性状而受到选择；其中HVC几乎完全受环境调控。基因型-环境互作对脑发育具有重要作用，或可作为维持加性遗传变异的机制，进而可能通过雌性选择推动性选择进程。本研究表明，选择或作用于调控鸣唱学习的基因，而非直接作用于其内在的神经解剖结构，并强调了环境条件对鸣禽鸣唱学习与神经发育的根本性重要性。