Department of Animal Science and Technology, National Taiwan University, Taipei, 106, Taiwan.
Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University, Taipei, 110 Taiwan.
Biol Open. 2020 Jan 29;9(1):bio048264. doi: 10.1242/bio.048264.
The sodium osmotic gradient is necessary for the initiation of brain ventricle inflation, but a previous study predicted that organic and inorganic osmolytes play equivalently important roles in osmotic homeostasis in astrocytes. To test whether organic osmoregulation also plays a role in brain ventricle inflation, the core component for volume-regulated anion and organic osmolyte channel, , was investigated in the zebrafish model. RT-PCR and whole-mount hybridization indicated that both genes were ubiquitously expressed through to 12 hpf, and around the ventricular layer of neural tubes and the cardiogenic region at 24 hpf. Knocking down either one paralog with morpholino oligos resulted in abnormalities in circulation at 32 hpf. Morpholino oligos or CRISPR interference against either paralog led to smaller brain ventricles at 24 hpf. Either or mRNA rescued the phenotypic penetrance in both and morphants. Supplementation of taurine in the E3 medium and overexpression mRNA also rescued and morphants. Our results indicate that the two zebrafish paralogs are maternal message genes and are ubiquitously expressed in early embryos. The two genes play redundant roles in the expansion of brain ventricles and the circulatory system and taurine contributes to brain ventricle expansion via the volume-regulated anion and organic osmolyte channels.
钠渗透梯度对于脑室内充气的启动是必要的，但之前的一项研究预测，有机和无机渗透物在星形胶质细胞的渗透稳态中同样发挥重要作用。为了测试有机渗透调节是否也在脑室内充气中发挥作用，研究人员在斑马鱼模型中研究了体积调节阴离子和有机渗透物通道的核心组件 。RT-PCR 和全胚胎原位杂交表明，这两个基因在 12 hpf 时普遍表达，在 24 hpf 时则在神经管的脑室层和心脏生成区周围表达。用 寡核苷酸将任一 基因敲低会导致 32 hpf 时循环异常。针对任一 基因的 寡核苷酸或 CRISPR 干扰会导致 24 hpf 时脑室内腔变小。 或 基因的 mRNA 均能挽救 和 突变体的表型穿透率。在 E3 培养基中补充牛磺酸以及过表达 mRNA 也能挽救 和 突变体。我们的结果表明，这两个斑马鱼 基因是母源信使基因，在早期胚胎中广泛表达。这两个基因在脑室内腔和循环系统的扩张中发挥冗余作用，牛磺酸通过体积调节阴离子和有机渗透物通道促进脑室内腔的扩张。
