Griffin K, Patient R, Holder N
Developmental Biology Research Centre, Randall Institute, King's College, London, UK.
Development. 1995 Sep;121(9):2983-94. doi: 10.1242/dev.121.9.2983.
To analyse the roles of FGF activity and brachyury during gastrulation we have directly compared the consequences of inhibition of FGF-receptor signalling with the phenotype of the zebrafish brachyury mutant, no tail (ntl). We show that expression of ntl is regulated by FGF and that inhibition of FGF receptor-signalling leads to complete loss of the trunk and tail. Since the ntl mutant lacks the tail and notochord but has an otherwise normal trunk, this demonstrates that trunk development is dependent upon an unidentified gene, or set of genes, referred to as no trunk (ntk) which is regulated by FGF. We propose a model to explain the FGF-dependent regulation of ntl and ntk that accounts for the above phenotypes. Consistent with this model, over-expression of eFGF led to suppression of anterior fates and development of trunk and tail derivatives only. In addition, widespread activation of convergence and extension movements resulted in the formation of multiple axis-like structures. Expression of eve1 and cad1 was also regulated by FGF activity, suggesting that during gastrulation FGF activity is normally restricted to the germ ring where these genes, and ntl, are expressed. Taken together these data suggest that the germ ring acts as a posteriorising centre during AP patterning, mediated by FGF activity in this tissue.
为了分析成纤维细胞生长因子（FGF）活性和短尾相关蛋白（brachyury）在原肠胚形成过程中的作用，我们直接比较了抑制FGF受体信号传导的后果与斑马鱼短尾相关蛋白突变体no tail（ntl）的表型。我们发现ntl的表达受FGF调控，抑制FGF受体信号传导会导致躯干和尾部完全缺失。由于ntl突变体没有尾巴和脊索，但躯干在其他方面正常，这表明躯干发育依赖于一个未确定的基因或一组基因，称为no trunk（ntk），它受FGF调控。我们提出了一个模型来解释ntl和ntk的FGF依赖性调控，该模型可以解释上述表型。与该模型一致，eFGF的过度表达导致前部命运的抑制，仅形成躯干和尾部衍生物。此外，广泛激活汇聚延伸运动导致形成多个轴状结构。eve1和cad1的表达也受FGF活性调控，这表明在原肠胚形成过程中，FGF活性通常局限于胚环，这些基因以及ntl在胚环中表达。综合这些数据表明，在前后轴模式形成过程中，胚环作为一个后化中心，由该组织中的FGF活性介导。
