Kruppel acts as a gap gene regulating expression of hunchback and even-skipped in the intermediate germ cricket Gryllus bimaculatus
Kruppel acts as a gap gene regulating expression of hunchback and even-skipped in the intermediate germ cricket Gryllus bimaculatus
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DOI：
10.1016/j.ydbio.2005.12.057
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发表时间：
2006-06-15
影响因子：
2.7
通讯作者：
Noji, Sumihare
中科院分区：
文献类型：
--
作者：
Mito, Taro;Okamoto, Haruko;Noji, Sumihare
果蝇是一种长胚芽昆虫，整个身体的分节同时发生。相反，在短和中间胚芽昆虫中，前节在胚盘阶段被指定，而其余的后节在后期阶段被指定。在果蝇胚胎中，由间隙基因编码的转录因子，如Kruppel，在合胞体环境中扩散并调节其他间隙、配对规则和Hox基因的表达。为了了解短胚和中间胚昆虫的分节机制，我们研究了Kr直系同源物（Gb'Kr）在中间胚昆虫双斑蟋蟀（Gryllus bimaculatus）发育中的作用。我们发现Gb'Kr在胚胎细胞化后的预期胸部区域以间隙模式表达。为了确定Gb'Kr在分割中的功能，我们使用RNA干扰（RNAi）分析敲低表型。Gb'Kr RNAi缺失导致间隙表型，其中第一胸段至第七腹段的后部缺失。通过对Hox基因在Gb'Kr RNAi胚胎中表达模式的分析，发现蟋蟀Hox基因与Kr基因之间的调控关系不同于另一种中间生殖昆虫Oncopeltus。此外，我们发现Gb'Kr直接或间接地调节hunchback的表达最低，甚至跳过，在预期的胸部区域。我们的研究结果表明，Gb'Kr是一个差距基因，在细胞环境中的行为，并需要分割在胸部和腹部地区通过调节差距和配对规则基因的表达。(c)2006年爱思唯尔公司All rights reserved.
In Drosophila, a long germ insect, segmentation occurs simultaneously across the entire body. In contrast, in short and intermediate germ insects, the anterior segments are specified during the blastoderm stage, while the remaining posterior segments are specified during later stages. In Drosophila embryos, the transcriptional factors coded by gap genes, such as Kruppel, diffuse in the syncytial environment and regulate the expression of other gap, pair-rule, and Hox genes. To understand the segmentation mechanisms in short and intermediate germ insects, we investigated the role of Kr ortholog (Gb'Kr) in the development of the intermediate germ insect Gryllus bimaculatus. We found that Gb'Kr is expressed in a gap pattern in the prospective thoracic region after cellularization of the embryo. To determine the function of Gb'Kr in segmentation, we analyzed knockdown phenotypes using RNA interference (RNAi). Gb'Kr RNAi depletion resulted in a gap phenotype in which the posterior of the first thoracic through seventh abdominal segments were deleted. Analysis of the expression patterns of Hox genes in Gb'Kr RNAi embryos indicated that regulatory relationships between Hox genes and Kr in Gryllus differ from those in Oncopeltus, another intermediate germ insect. Furthermore, we found that Gb'Kr regulates expression minimally of hunchback and even-skipped, directly or indirectly, in the prospective thoracic region. Our findings suggest that Gb'Kr is a gap gene that acts in the cellular environment and is required for segmentation in the thoracic and abdominal regions through the regulation of gap and pair-rule gene expression. (c) 2006 Elsevier Inc. All rights reserved.