Temporal profile of brain gene expression associated with learning in an anuran amphibian

Reported here are the transcriptomic changes resulting from learning, in the brain of an anuran amphibian. RNA sequencing was utilized to investigate temporal gene expression patterns resulting from conditioned learning in the fire-bellied toad, Bombina orientalis. As a basal tetrapod lineage, B. orientalis represents a robust candidate for investigating the evolution of molecular mechanisms underlying learning in vertebrates. Differential expression following learning reveled activity in molecular pathways related to immediate early gene expression, cytoskeletal modification, axon guidance activity, and apoptotic processes. Learning in the fire-bellied toad is characterized by early IEG activity coinciding with transcriptional activity and structural modification, followed by axon guidance and adhesion activity, and late neural pruning. Overall design: Experiment consisted of three treatments + control with three replicates each. Treatments represent post-training sacrifice timing (2 hours, 4 hours, and 24 hours), with an unmanipulated control. n=12.

本研究报道了无尾两栖类动物大脑中学习诱导的转录组变化。本研究采用RNA测序（RNA sequencing）技术，探究了东方铃蟾（Bombina orientalis）经条件化学习后的时序基因表达模式。作为基底四足动物类群，东方铃蟾是研究脊椎动物学习相关分子机制演化的理想候选模型。学习诱导的差异表达分析揭示了即刻早期基因（immediate early gene, IEG）表达、细胞骨架重塑、轴突导向及细胞凋亡过程相关的分子通路活性变化。东方铃蟾的学习过程具有阶段性特征：早期即刻早期基因活性与转录活性及结构重塑同步出现，随后伴随轴突导向与细胞黏附活性的激活，最终在晚期发生神经修剪。实验整体设计：设置三组处理组与一组对照组，每组均设置3次生物学重复。处理组分别对应训练后2小时、4小时及24小时三个采样处死时间点，对照组为未进行任何操作的个体。本实验共包含12个样本（n=12）。