Linus Pauling Institute, Oregon State University, 307 LPSC, Corvallis, OR, USA.
Molecular and Cell Biology Program, Oregon State University, Corvallis, OR, USA.
Sci Rep. 2020 Sep 21;10(1):15028. doi: 10.1038/s41598-020-71760-x.
Vitamin E (VitE) deficiency results in embryonic lethality. Knockdown of the gene ttpa encoding for the VitE regulatory protein [α-tocopherol transfer protein (α-TTP)] in zebrafish embryos causes death within 24 h post-fertilization (hpf). To test the hypothesis that VitE, not just α-TTP, is necessary for nervous system development, adult 5D strain zebrafish, fed either VitE sufficient (E+) or deficient (E-) diets, were spawned to obtain E+ and E- embryos, which were subjected to RNA in situ hybridization and RT-qPCR. Ttpa was expressed ubiquitously in embryos up to 12 hpf. Early gastrulation (6 hpf) assessed by goosecoid expression was unaffected by VitE status. By 24 hpf, embryos expressed ttpa in brain ventricle borders, which showed abnormal closure in E- embryos. They also displayed disrupted patterns of paired box 2a (pax2a) and SRY-box transcription factor 10 (sox10) expression in the midbrain-hindbrain boundary, spinal cord and dorsal root ganglia. In E- embryos, the collagen sheath notochord markers (col2a1a and col9a2) appeared bent. Severe developmental errors in E- embryos were characterized by improper nervous system patterning of the usually carefully programmed transcriptional signals. Histological analysis also showed developmental defects in the formation of the fore-, mid- and hindbrain and somites of E- embryos at 24 hpf. Ttpa expression profile was not altered by the VitE status demonstrating that VitE itself, and not ttpa, is required for development of the brain and peripheral nervous system in this vertebrate embryo model.
维生素 E(VitE)缺乏会导致胚胎致死。在斑马鱼胚胎中敲低编码 VitE 调节蛋白[α-生育酚转移蛋白(α-TTP)]的 ttpa 基因会导致受精后 24 小时内死亡。为了验证 VitE 而不仅仅是 α-TTP 对神经系统发育是必需的假设,用 VitE 充足(E+)或缺乏(E-)饮食喂养的成年 5D 品系斑马鱼进行繁殖,以获得 E+和 E-胚胎,然后对其进行 RNA 原位杂交和 RT-qPCR。在 12 hpf 之前,ttpa 在胚胎中广泛表达。通过 goosecoid 表达评估的早期原肠胚形成(6 hpf)不受 VitE 状态的影响。到 24 hpf 时,胚胎在脑室边界表达 ttpa,在 E-胚胎中观察到脑室异常闭合。它们还显示出中脑-后脑边界、脊髓和背根神经节中配对盒 2a(pax2a)和 SRY 盒转录因子 10(sox10)表达模式中断。在 E-胚胎中,脊索的胶原鞘标志物(col2a1a 和 col9a2)似乎弯曲。E-胚胎的严重发育错误的特征是神经系统的正常精心编程的转录信号的不当模式。组织学分析还显示,E-胚胎在 24 hpf 时前脑、中脑和后脑以及体节的形成中存在发育缺陷。VitE 状态没有改变 ttpa 的表达谱,这表明在这种脊椎动物胚胎模型中,VitE 本身而不是 ttpa 是大脑和周围神经系统发育所必需的。