Knockdown of Parhyale Ultrabithorax recapitulates evolutionary changes in crustacean appendage morphology
Knockdown of Parhyale Ultrabithorax recapitulates evolutionary changes in crustacean appendage morphology
复制标题
DOI：
10.1073/pnas.0903105106
复制
发表时间：
2009-08-18
影响因子：
11.1
通讯作者：
Patel, Nipam H.
中科院分区：
文献类型：
--
作者：
Liubicich, Danielle M.;Serano, Julia M.;Patel, Nipam H.
甲壳类动物拥有非常多样化的附肢，无论是在单个个体的体节之间还是在物种之间。以前的研究表明，在广泛的甲壳类动物的同源异型（Hox）基因Ultrabithorax（Ubx）的前表达边界和专门的胸部喂养附属物，称为上颌骨的位置和数量之间的相关性。考虑到Hox基因调节不同生物的区域身份，如小鼠和苍蝇，这些观察甲壳类动物导致的假设，Ubx的表达调节的数量的颚足类和Ubx表达的进化变化产生了甲壳类动物的附肢多样性的各个方面。具体而言，进化的变化，在表达边界的UBX导致甲壳类动物的物种，无论是0，1，2，或3对胸上颌骨。在这里，我们通过改变夏威夷Parhyale，甲壳类动物，通常拥有一个单一的对上颌骨的UBX的表达来测试这一假设。通过减少Ubx的表达，我们可以产生Parhyale与其他甲壳类物种中看到的模式，让人想起额外的上颌骨，这些形态学上的改变保持为动物蜕皮和成熟。这些结果提供了关键的证据支持的命题，UBX表达的变化在产生甲壳类动物的附肢多样性发挥了作用，并提供一般的见解形态进化的机制。
Crustaceans possess remarkably diverse appendages, both between segments of a single individual as well as between species. Previous studies in a wide range of crustaceans have demonstrated a correlation between the anterior expression boundary of the homeotic (Hox) gene Ultrabithorax (Ubx) and the location and number of specialized thoracic feeding appendages, called maxillipeds. Given that Hox genes regulate regional identity in organisms as diverse as mice and flies, these observations in crustaceans led to the hypothesis that Ubx expression regulates the number of maxillipeds and that evolutionary changes in Ubx expression have generated various aspects of crustacean appendage diversity. Specifically, evolutionary changes in the expression boundary of Ubx have resulted in crustacean species with either 0, 1, 2, or 3 pairs of thoracic maxillipeds. Here we test this hypothesis by altering the expression of Ubx in Parhyale hawaiensis, a crustacean that normally possesses a single pair of maxillipeds. By reducing Ubx expression, we can generate Parhyale with additional maxillipeds in a pattern reminiscent of that seen in other crustacean species, and these morphological alterations are maintained as the animals molt and mature. These results provide critical evidence supporting the proposition that changes in Ubx expression have played a role in generating crustacean appendage diversity and lend general insights into the mechanisms of morphological evolution.