Nodal信号在脊椎动物胚胎发育的中内胚层诱导、左右不对称性的建立、神经外胚层沿前后轴线的分化等方面起着重要的作用.为鉴定受Nodal信号调控的基因,特别是那些转录因子基因,通过将来自squint过量表达、缺失Nodal信号的MZoep突变体或野生型30%外包期胚胎的RNA与Affymetrix斑马鱼寡核苷酸芯片杂交.发现与野生型样本相比,在squint过量表达的样本中,265个转录本的表达显著增强(log2ratio〉1),111个转录本的表达显著减弱(log2ratio〈-1);在MZoep样本中,表达显著增强的(log2ratio〉1)转录本有1495个,表达显著减弱(log2ratio〈-1)的有550个.squint过量表达使26个转录因子基因的表达增强,11个转录因子基因的表达减弱;另一方面,MZoep突变体中表达增强的转录因子基因为69个,表达减弱的转录因子基因为30个.这些结果为进一步研究Nodal信号的转导机理和生物学功能提供了有益的数据.
Nodal signals play important roles in mesendoderm induction, establishment of left-right asymmetry and anteroposterior patterning of the neuroectoderm during vertebrate embryogenesis. It is aimed at identifying Nodal-regulated genes in zebrafish embryos, particularly those encoding transcription factors. A (Affymetrix) genechip analysis was performed using RNAs derived from embryos injected with squint mRNA, MZoep mutant embryos that are deficient in Nodal signaling, and wildtype embryos at the 30% epiboly stage. Transcripts (genes) with at least two-fold changes in expression level between wildtype and the other samples were identified. In squint mRNA-injected embryos, 265 transcripts show an increased expression level and 111 have a decreased expression level; in MZoep embryos, the expression of 1 495 transcripts increases while 550 transcripts express at a decreased level. Furthermore, overexpression of squint causes increased expression of 26 and decreased expression of 11 annotated transcription factor genes; in MZoep embryos, the number of trans.cription factor genes showing an increase and decrease of expression are 69 and 30, respectively. These results would provide useful information for further studying mechanisms and biological functions of Nodal signal transduction.