Kruppel is a gap gene in the intermediate germband insect Oncopeltus fasciatus and is required for development of both blastoderm and germ band-derived segments
Kruppel is a gap gene in the intermediate germband insect Oncopeltus fasciatus and is required for development of both blastoderm and germ band-derived segments
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DOI：
10.1242/dev.01311
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发表时间：
2004-09-01
期刊：
影响因子：
4.6
通讯作者：
Kaufman, TC
中科院分区：
文献类型：
--
作者：
Liu, PZ;Kaufman, TC
长胚带昆虫（如果蝇）的分割基本上同时发生在整个身体上。一系列的分割基因通过胚盘的细分使胚胎沿其前后轴沿着排列。这与短胚带和中间胚带分割模式形成鲜明对比，其中前段在胚盘阶段形成，其余的后段在后期从后生长区产生。短胚和中胚昆虫体节发生的双相性意味着胚盘和胚带体节可能存在不同的形成机制。在果蝇中，差距基因Kruppel是胚胎中央部分正常形成所必需的。果蝇中Kruppel活性的这一结构域对应于短胚带和中间胚带昆虫中跨越胚盘和胚带衍生片段的区域。我们已经克隆了Kruppel同源物从马利筋错误，Oncopeltus fasciatus（半翅目，Lygaeidae），中间生殖带昆虫。我们发现Oncopeltus Kruppel在胚胎发育的胚盘和胚带阶段在胸部的间隙样结构域中表达。为了研究Kruppel在Oncopeltus分割中的功能，我们使用RNAi产生敲低表型。Oncopeltus中Kruppel活性的丧失导致大间隙表型，通过第四腹节的中胸的丧失。此外，我们发现，Kruppel是必需的，以抑制前部和后部的Hox基因的表达在中央部分的胚带。我们的研究结果表明，Kruppel是所需的胚盘衍生和胚带衍生的部分，并表明Kruppel功能在很大程度上是保守的Oncopeltus和果蝇，尽管他们的分歧胚胎发生。
Segmentation in long germband insects such as Drosophila occurs essentially simultaneously across the entire body. A cascade of segmentation genes patterns the embryo along its anterior-posterior axis via subdivision of the blastoderm. This is in contrast to short and intermediate germband modes of segmentation where the anterior segments are formed during the blastoderm stage and the remaining posterior segments arise at later stages from a posterior growth zone. The biphasic character of segment generation in short and intermediate germ insects implies that different formative mechanisms may be operating in blastoderm-derived and germband-derived segments. In Drosophila, the gap gene Kruppel is required for proper formation of the central portion of the embryo. This domain of Kruppel activity in Drosophila corresponds to a region that in short and intermediate germband insects spans both blastoderm, and germband-derived segments. We have cloned the Kruppel homolog from the milkweed bug, Oncopeltus fasciatus (Hemiptera, Lygaeidae), an intermediate germband insect. We find that Oncopeltus Kruppel is expressed in a gap-like domain in the thorax during the blastoderm and germband stages of embryogenesis. In order to investigate the function of Kruppel in Oncopeltus segmentation, we generated knockdown phenotypes using RNAi. Loss of Kruppel activity in Oncopeltus results in a large gap phenotype, with loss of the mesothoracic through fourth abdominal segments. Additionally, we find that Kruppel is required to suppress both anterior and posterior Hox gene expression in the central portion of the germband. Our results show that Kruppel is required for both blastoderm-derived and germband-derived segments and indicate that Kruppel function is largely conserved in Oncopeltus and Drosophila despite their divergent embryogenesis.