Antenna and all gnathal appendages are similarly transformed by homothorax knock-down in the cricket Gryllus bimaculatus
Antenna and all gnathal appendages are similarly transformed by homothorax knock-down in the cricket Gryllus bimaculatus
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DOI：
10.1016/j.ydbio.2007.09.059
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发表时间：
2008-01-01
影响因子：
2.7
通讯作者：
Klingler, Martin
中科院分区：
文献类型：
--
作者：
Ronco, Monica;Uda, Tomohiro;Klingler, Martin
我们的理解的发展机制下的节肢动物的附属物的多样性很大程度上取决于特殊的情况下，双翅目果蝇黑腹。在这种昆虫中，同胸（hth）和齿外体（exd）共同在附肢模式和身份中起着关键作用。我们调查的作用，hth同源蟋蟀双斑的父母RNA干扰。该物种具有比Oncopeltus fasciatus更一般化的形态，Oncopeltus fasciatus是除果蝇之外的另一种昆虫，其中已研究了同胸功能。蟋蟀的头部附属物代表了形态学上的原始状态，包括昆虫典型的下颌骨、上颌骨和唇，这些结构在Oncopeltus和果蝇中高度修饰或缺失。我们通过亲本RNAi消除了Gb'hth功能，以研究其对其他附属物基因（Gb'wingless，Gb'dachshund，Gb'aristaless和Gb'Distalless）的适当调控的需要，并分析了蟋蟀的末端表型。Gb'hth RNAi突变体与果蝇中的hth突变体或功能缺失克隆相似，显示同源异型和节段缺陷。然而，有趣的是，我们发现在Gb'hth RNAi中，不仅触角而且所有的蚊蚋附属物都发生了同源转化，使得所有的头部附属物远端分化为腿，近端分化为触角。因此，Gb'hth并不是触角命运的特定要求，但在所有头部附属物的规格中扮演类似的角色。这表明hth在昆虫触角中的作用与其在更后节中作为节特异性同源异型基因的辅因子的功能没有根本的不同。(c)2007年爱思唯尔公司所有的战斗保留。
Our understanding of the developmental mechanisms underlying the vast diversity of arthropod appendages largely rests on the peculiar case of the dipteran Drosophila melanogaster. In this insect, homothorax (hth) and extradenticle (exd) together play a pivotal role in appendage patterning and identity. We investigated the role of the hth homologue in the cricket Gryllus bimaculatus by parental RNA interference. This species has a more generalized morphology than Oncopeltus fasciatus, the one other insect besides Drosophila where homothorax function has been investigated. The Gryllus head appendages represent the morphologically primitive state including insect-typical mandibles, maxillae and labium, structures highly modified or missing in Oncopeltus and Drosophila. We depleted Gb'hth function through parental RNAi to investigate its requirement for proper regulation of other appendage genes (Gb'wingless, Gb'dachshund, Gb'aristaless and Gb'Distalless) and analyzed the terminal phenotype of Gryllus nymphs. Gb'hth RNAi nymphs display homeotic and segmentation defects similar to hth mutants or loss-of-function clones in Drosophila. Intriguingly, however, we find that in Gb'hth RNAi nymphs not only the antennae but also all gnatbal appendages are homeotically transformed, such that all head appendages differentiate distally as legs and proximally as antennae. Hence, Gb'hth is not specifically required for antennal fate, but fulfills a similar role in the specification of all head appendages. This suggests that the role of hth in the insect antenna is not fundamentally different from its function as cofactor of segment-specific homeotic genes in more posterior segments. (c) 2007 Elsevier Inc. All fights reserved.