Lemaire Laurence A, Cao Chen, Yoon Peter H, Long Juanjuan, Levine Michael
Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.
Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
Sci Adv. 2021 Apr 28;7(18). doi: 10.1126/sciadv.abf7452. Print 2021 Apr.
The hypothalamus coordinates neuroendocrine functions in vertebrates. To explore its evolutionary origin, we describe integrated transcriptome/connectome brain maps for swimming tadpoles of , which serves as an approximation of the ancestral proto-vertebrate. This map features several cell types related to different regions of the vertebrate hypothalamus, including the mammillary nucleus, the arcuate nucleus, and magnocellular neurons. Coronet cells express melanopsin and share additional properties with the saccus vasculosus, a specialized region of the hypothalamus that mediates photoperiodism in nontropical fishes. Comparative transcriptome analyses identified orthologous cell types for mechanosensory switch neurons, and and relay neurons in different regions of the mouse hypothalamus. These observations provide evidence that the hypothalamus predates the evolution of the vertebrate brain. We discuss the possibility that switch neurons, coronet cells, and / relay neurons comprise a behavioral circuit that helps trigger metamorphosis of larvae in response to twilight.
下丘脑协调脊椎动物的神经内分泌功能。为了探究其进化起源，我们描述了 （此处原文缺失具体物种名称） 游泳蝌蚪的综合转录组/连接组脑图谱，它可作为原始脊椎动物的近似模型。该图谱具有几种与脊椎动物下丘脑不同区域相关的细胞类型，包括乳头体核、弓状核和大细胞神经元。冠状细胞表达黑视蛋白，并与血管囊具有其他共同特性，血管囊是下丘脑的一个特殊区域，可介导非热带鱼类的光周期现象。比较转录组分析确定了小鼠下丘脑不同区域中机械感觉转换神经元以及 （此处原文缺失具体内容） 和 （此处原文缺失具体内容） 中继神经元的直系同源细胞类型。这些观察结果提供了证据表明下丘脑在脊椎动物大脑进化之前就已存在。我们讨论了转换神经元、冠状细胞以及 （此处原文缺失具体内容） /中继神经元组成一个行为回路的可能性，该回路有助于触发 （此处原文缺失具体物种名称） 幼虫在黄昏时的变态。
