Zeppilli S, Gurrola A Ortega, Demetci P, Brann D H, Attey R, Zilkha N, Kimchi T, Datta S R, Singh R, Tosches M A, Crombach A, Fleischmann A
bioRxiv. 2023 Aug 14:2023.08.13.553130. doi: 10.1101/2023.08.13.553130.
The cerebral cortex diversified extensively during vertebrate evolution. Intriguingly, the three-layered mammalian olfactory cortex resembles the cortical cytoarchitecture of non-mammals yet evolved alongside the six-layered neocortex, enabling unique comparisons for investigating cortical neuron diversification. We performed single-nucleus multiome sequencing across mouse three- to six-layered cortices and compared neuron types across mice, reptiles and salamander. We identified neurons that are olfactory cortex-specific or conserved across mouse cortical areas. However, transcriptomically similar neurons exhibited area-specific epigenetic states. Additionally, the olfactory cortex showed transcriptomic divergence between lab and wild-derived mice, suggesting enhanced circuit plasticity through adult immature neurons. Finally, olfactory cortex neurons displayed marked transcriptomic similarities to reptile and salamander neurons. Together, these data indicate that the mammalian olfactory cortex retains molecular signatures representative of ancestral cortical traits.
在脊椎动物进化过程中，大脑皮层经历了广泛的多样化。有趣的是，三层结构的哺乳动物嗅觉皮层类似于非哺乳动物的皮层细胞结构，但它是与六层结构的新皮层一同进化的，这使得我们能够进行独特的比较，以研究皮层神经元的多样化。我们对小鼠三到六层皮层进行了单核多组学测序，并比较了小鼠、爬行动物和蝾螈的神经元类型。我们鉴定出了嗅觉皮层特异性的神经元或在小鼠皮层区域中保守的神经元。然而，转录组学上相似的神经元表现出区域特异性的表观遗传状态。此外，嗅觉皮层在实验室小鼠和野生来源小鼠之间表现出转录组差异，这表明成年未成熟神经元增强了回路可塑性。最后，嗅觉皮层神经元与爬行动物和蝾螈神经元表现出显著的转录组相似性。总之，这些数据表明哺乳动物嗅觉皮层保留了代表祖先皮层特征的分子特征。
