School of Biosciences, University of Exeter, Exeter, United Kingdom.
J Exp Zool B Mol Dev Evol. 2010 May 15;314(3):187-95. doi: 10.1002/jez.b.21325.
Due to their large yolk size, salmonid embryos take a longer time for epiboly movements and germ ring closure compared with most other teleost species. Here we analyzed the germ ring closure, tail bud formation and development of the notochord and somites in rainbow trout using live embryo imaging and in situ hybridization with the rt-ntl probe. Rt-ntl is expressed in the germ ring (blastula, gastrula and somitogenesis stage), notochord, tail bud and somites (somitogenesis stage). When epiboly covers half the yolk, a tail bud-like structure is formed and somitogenesis starts. By the time epiboly is completed, the yolk covered and the germ ring closed, the embryo has already reached the 20 somite stage. Therefore, the timing of germ ring closure and tail bud formation is reversed in trout embryos compared with zebrafish and other small model fish embryos (heterochrony). Based on this result, we re-examined the definition of tail bud formation.
由于卵黄大小较大，与大多数其他硬骨鱼类相比，鲑鱼胚胎的胚环运动和胚环闭合需要更长的时间。在这里，我们使用活体胚胎成像和 rt-ntl 探针的原位杂交技术分析了虹鳟鱼的胚环闭合、尾芽形成和脊索及体节的发育。Rt-ntl 在胚环（囊胚、原肠胚和体节形成阶段）、脊索、尾芽和体节（体节形成阶段）中表达。当胚环覆盖卵黄的一半时，形成类似于尾芽的结构，体节形成开始。当胚环完全覆盖卵黄并闭合时，胚胎已经达到 20 个体节阶段。因此，与斑马鱼和其他小型模式鱼胚胎（异时性）相比，鲑鱼胚胎的胚环闭合和尾芽形成的时间是相反的。基于这一结果，我们重新检查了尾芽形成的定义。
