Expression, function and regulation of Brachyenteron in the short germband insect Tribolium castaneum
Expression, function and regulation of Brachyenteron in the short germband insect Tribolium castaneum
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DOI：
10.1007/s00427-008-0210-7
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发表时间：
2008-04-01
影响因子：
2.4
通讯作者：
Reuter, Rolf
中科院分区：
文献类型：
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作者：
Berns, Nicola;Kusch, Thomas;Reuter, Rolf
T结构域转录因子参与了脊椎动物和无脊椎动物胚胎发生过程中的许多不同过程，如中胚层、心脏或肠道发育。在昆虫中，已知以下五种类型的T-box基因：短肠（brachyenteron，byn）、optomotor-blind（omb）、optomotor-blind-related-gene-1（org-1）、dorsocross（doc）和H15。由于所有这些类别都存在于果蝇和面粉甲虫Tribolium的基因组中，因此这五种类型的基因的多样性从双翅目到甲虫各不相同。在高等双翅目中，存在三个doc基因（doc 1-doc 3）的小簇，而拟谷盗基因组仅包含单个Tc-doc基因。与果蝇中的单个H15基因相比，赤拟谷盗基因组中存在两个H15基因，Tc-H15 a和Tc-H15 b。我们分析了Tribolium brachyenteron直系同源物（Tc-byn）的表达和功能。在胚胎发育过程中，Tc-byn是专门在生长区的延伸生殖带，后来成为局限于远端直肠和后肠，这种情况下，平行的表达模式的果蝇byn。Tc-byn-RNAi处理的胚胎表型复制果蝇byn突变体，并且不形成后肠。此外，我们已经表征了Tc-byn转录起始位点上游的调控元件，其赋予果蝇胚胎发育中的后肠中的特定基因表达。我们的研究结果表明，Brachyury型转录调控因子在表达、功能和调控水平上在昆虫后肠发育中具有高度保守的作用。
T-domain transcription factors are involved in many different processes during embryogenesis, such as mesoderm, heart or gut development in vertebrates and in invertebrates. In insects, the following five types of T-box genes are known: brachyenteron (byn), optomotor-blind (omb), optomotor-blind-related-gene-1 (org-1), dorsocross (doc) and H15. As all these classes are present in the genome of the fruit fly Drosophila melanogaster and the flour beetle Tribolium, the multiplicity of the five types of genes varies from dipterans to the beetle. In higher dipterans, a small cluster of three doc genes (doc1-doc3) exists, while the Tribolium genome contains a single Tc-doc gene only. Two H15 genes, Tc-H15a and Tc-H15b, are present in the Tribolium genome compared to a single H15 gene in Drosophila. We have analysed the expression and function of the Tribolium brachyenteron ortholog (Tc-byn). During embryogenesis, Tc-byn is exclusively expressed in the growth zone of the extending germband and later becomes confined to the distal proctodeum and the hindgut, a situation that parallels the expression pattern of byn in Drosophila. Tc-byn-RNAi treated embryos phenocopy Drosophila byn mutants and form no hindgut. In addition, we have characterised a regulatory element upstream of the Tc-byn transcription start site that confers specific gene expression in the developing hindgut of the Drosophila embryo. Our results demonstrate a highly conserved role for Brachyury-type transcriptional regulators in posterior gut development of insects at the level of expression, function and regulation.