School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi Ishikawa 923-1292, Japan.
J Biosci Bioeng. 2012 Jun;113(6):683-8. doi: 10.1016/j.jbiosc.2012.02.002. Epub 2012 Apr 6.
DAX1 is an orphan nuclear receptor and involved in development of steroidogenic organs, which activates transcription of genes involved in steroidogenesis. In this study, we analyzed the function of the zebrafish dax1 during early development of central nervous systems to appear unidentified aspects of DAX1 and decrease confusions concerned with functions of DAX1 in early development of vertebrates. By whole-mount in situ hybridization of embryo at the 32 h post fertilization (hpf), expression of zebrafish dax1 was detected around the forebrain, midbrain, hindbrain, and the extending tail tip. Embryos injected with zebrafish dax1 morpholino antisense nucleotide (MO) exhibited delayed development. When the developmental stage of wild type embryos was at Prim-15 (32 hpf), zebrafish dax1MO injected embryos were at Prim-5 (24 hpf). Concurrently with developmental delay, the MO injected embryos showed high mortality. At 48 hpf, the MO injected embryos exhibited abnormal development in the central nervous systems. The enlarged tectum and the protruded rhombomeres were observed. Moreover, development of central nervous systems, especially midbrain-hindbrain boundary, became narrower. At 5 day post fertilization, the MO injected embryos formed edemas around head, pericardial sac and abdomen. Collectively, our results indicated that the zebrafish dax1 is important for brain development.
DAX1 是一种孤儿核受体，参与类固醇生成器官的发育，它能激活类固醇生成基因的转录。在这项研究中，我们分析了斑马鱼 dax1 在中枢神经系统早期发育过程中的功能，以揭示 DAX1 的未知方面，并减少与 DAX1 在脊椎动物早期发育中功能相关的混淆。通过对受精后 32 小时（hpf）胚胎的全胚胎原位杂交，检测到斑马鱼 dax1 在大脑前部、中脑、后脑和延伸的尾端周围表达。用斑马鱼 dax1 基因的反义核苷酸（MO）注射的胚胎表现出发育迟缓。当野生型胚胎的发育阶段处于 Prim-15（32 hpf）时，斑马鱼 dax1MO 注射的胚胎处于 Prim-5（24 hpf）。与发育迟缓同时发生的是，MO 注射的胚胎死亡率很高。在 48 hpf 时，MO 注射的胚胎表现出中枢神经系统的异常发育。观察到脑顶盖增大和菱形脑节突出。此外，中枢神经系统的发育，特别是中脑-后脑边界变得更窄。在受精后 5 天，MO 注射的胚胎头部、心包和腹部周围形成水肿。总之，我们的结果表明，斑马鱼 dax1 对大脑发育很重要。
