Weighted gene coexpression analysis of RNA-seq data from 65d juvenile Area X and adjacent non-song ventral striatopallidum (VSP).. Taeniopygia guttata

Human speech is one of the few examples of vocal learning among mammals, yet ~half of avian species exhibit this ability. Its genetic basis is unknown beyond a shared requirement for FoxP2 in both humans and zebra finches. Here we manipulated FoxP2 isoforms in Area X during a critical period for song development, delineating, for the first time, unique contributions of each to vocal learning. We used weighted gene coexpression network analysis of RNA-seq data to construct transcriptional profiles and found gene modules correlated to singing, learning, or vocal variability. The juvenile song modules were preserved adults, whereas the learning modules were not. The learning modules were preserved in the striatopallidum adjacent to Area X whereas the song modules were not. The confluence of learning and singing coexpression in juvenile, but not adult, Area X may underscore molecular processes that drive vocal learning in zebra finches and, by analogy, humans. Overall design: 19 samples each from Area X and VSP for birds injected in Area X with AAV1 to overexpress GFP, full length FoxP2, or truncated FoxP2. Biological replicates but not technical replicates are included.

人类言语是哺乳动物中为数不多的发声学习案例之一，而约半数鸟类物种具备该能力。该能力的遗传基础尚未完全阐明，目前仅明确人类与斑胸草雀（zebra finches）均依赖叉头框P2（FoxP2）基因发挥功能。本研究在鸣曲发育关键时期对X脑区（Area X）内的FoxP2剪接异构体进行了操控，首次明确了每种异构体在发声学习中的独特作用。本研究通过对RNA测序（RNA-seq）数据开展加权基因共表达网络分析（weighted gene coexpression network analysis），构建了转录组特征，并鉴定出与鸣唱、学习或发声变异相关的基因模块。幼年鸣唱相关基因模块在成体中得以保留，而学习相关基因模块则未出现该现象。学习相关基因模块在X脑区邻近的纹状体苍白球区（striatopallidum）中得以保留，而鸣唱相关基因模块则无此现象。幼年X脑区内同时存在与学习和鸣唱相关的共表达特征，而成体则无此现象，这一现象或可揭示驱动斑胸草雀发声学习的分子机制，类推至人类亦具有参考价值。实验总体设计：向斑胸草雀X脑区注射腺相关病毒1型（AAV1）以过表达绿色荧光蛋白（GFP）、全长FoxP2或截短型FoxP2，分别从X脑区与VSP采集19份样本；实验仅设置生物学重复，未设置技术重复。