Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China.
Institute of Evolution & Marine Biodiversity and Department of Marine Biology, Ocean University of China, Qingdao 266003, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao 266003, China.
Int J Biol Macromol. 2020 Jan 1;142:384-394. doi: 10.1016/j.ijbiomac.2019.09.109. Epub 2019 Oct 5.
Amphioxus belongs to the subphylum cephalochordata, an extant representative of the most basal chordates, whose regulation of endocrine system remains ambiguous. Here we clearly demonstrated the existence of a functional GRP neuropeptide in amphioxus, which was able to interact with GRP receptor, activate both PKC and PKA pathways, increase gh, igf, and vegf expression. We also showed that the transcription level of amphioxus grp was affected by temperature and light, indicating the role of this gene in the regulation of energy balance and circadian rhythms. In addition, the expression of the amphioxus grp was detected in cerebral vesicle that has been proposed to be the homologous organ of vertebrate brain. These data collectively suggested that a functional GRP neuropeptide had already emerged in amphioxus, which provided insights into the evolutionary origin of GRP in chordate and the functional homology between the cerebral vesicle and vertebrate brain.
文昌鱼属于头索动物亚门，是现存最原始脊索动物的代表，其内分泌系统的调控尚不清楚。在这里，我们清楚地证明了文昌鱼中存在一种功能性 GRP 神经肽，它能够与 GRP 受体相互作用，激活 PKC 和 PKA 途径，增加 gh、igf 和 vegf 的表达。我们还表明，文昌鱼 grp 的转录水平受到温度和光照的影响，这表明该基因在调节能量平衡和昼夜节律中的作用。此外，在被认为是脊椎动物大脑同源器官的脑泡中检测到了文昌鱼 grp 的表达。这些数据共同表明，一种功能性的 GRP 神经肽已经在文昌鱼中出现，这为 GRP 在脊索动物中的进化起源以及脑泡与脊椎动物大脑之间的功能同源性提供了线索。
