van der Hoeven F, Sordino P, Fraudeau N, Izpisúa-Belmonte J C, Duboule D
Department of Zoology and Animal Biology, University of Geneva, Switzerland.
Mech Dev. 1996 Jan;54(1):9-21. doi: 10.1016/0925-4773(95)00455-6.
In tetrapods, Hox genes are essential for the proper organization and development of axial structures. Experiments involving Hox gene inactivations have revealed their particularly important functions in the establishment of morphological transitions within metameric series such as the vertebral column. Teleost fish show a much simpler range of axial (trunk or appendicular) morphologies, which prompted us to investigate the nature of the Hox system in these lower vertebrates. Here, we show that fish have a family of Hox genes, very similar in both number and general organization, to that of tetrapods. Expression studies, carried out with HoxD and HoxA genes, showed that all vertebrates use the same general scheme, involving the colinear activation of gene expression in both space and time. Comparisons between tetrapods and fish allowed us to propose a model which accounts for the primary function of this gene family. In this model, a few ancestral Hox genes were involved in the determination of polarity in the digestive tract and were further recruited in more elaborate axial structures.
在四足动物中，Hox基因对于轴结构的正常组织和发育至关重要。涉及Hox基因失活的实验揭示了它们在诸如脊柱等分节系列中形态转变的建立过程中具有特别重要的功能。硬骨鱼的轴向（躯干或附肢）形态范围要简单得多，这促使我们研究这些低等脊椎动物中Hox系统的本质。在这里，我们表明鱼类拥有一个Hox基因家族，其数量和总体组织与四足动物的非常相似。对HoxD和HoxA基因进行的表达研究表明，所有脊椎动物都使用相同的一般模式，包括基因表达在空间和时间上的共线性激活。通过对四足动物和鱼类的比较，我们提出了一个模型，该模型解释了这个基因家族的主要功能。在这个模型中，一些原始的Hox基因参与了消化道极性的确定，并在更复杂的轴结构中进一步被招募。
