The genetic factors of bilaterian evolution

The Cambrian explosion was a unique animal radiation ~540 million years ago that produced the full range of body plans across bilaterians. The genetic mechanisms underlying these events are unknown, leaving a fundamental question in evolutionary biology unanswered. Using large-scale comparative genomics and advanced orthology evaluation techniques, we identified 157 genes with bilaterian origin. Bilaterian innovations include the entire Nodal pathway, a key regulator of mesoderm development and left-right axis specification; components for nervous system development, including a suite of G protein-coupled receptors that control physiology and behaviour, the Robo-Slit midline repulsion system, and the neurotrophin signalling system; a high number of zinc finger transcription factors; and novel factors that previously escaped attention. Contradicting the current view, our study reveals that genes with bilaterian origin are robustly associated with key features in extant bilaterians, sugge...

寒武纪大爆发是约5.4亿年前一次独特的动物辐射事件，在两侧对称动物（bilaterians）中产生了所有门类的躯体构型。这些事件背后的遗传机制尚不明确，使得进化生物学中的一个基本问题悬而未决。通过大规模比较基因组学和先进的直系同源性评估技术，我们鉴定出157个起源于两侧对称动物的基因。两侧对称动物的创新包括完整的Nodal通路——这是中胚层发育和左右轴特化的关键调控因子；神经系统发育相关组件，包括一系列控制生理和行为的G蛋白偶联受体（G protein-coupled receptors）、Robo-Slit中线排斥系统以及神经营养因子信号系统；大量锌指转录因子；以及此前未被关注的新因子。与当前观点相悖，我们的研究揭示，起源于两侧对称动物的基因与现存两侧对称动物的关键特征存在强关联，这表明...