Characterization of a lamellocyte transcriptional enhancer located within the misshapen gene of Drosophila melanogaster.
Characterization of a lamellocyte transcriptional enhancer located within the misshapen gene of Drosophila melanogaster.
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DOI：
10.1371/journal.pone.0006429
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发表时间：
2009-07-29
期刊：
影响因子：
3.7
通讯作者：
Schulz RA
中科院分区：
文献类型：
--
作者：
Tokusumi T;Sorrentino RP;Russell M;Ferrarese R;Govind S;Schulz RA
果蝇已经成为研究造血的细胞和遗传方面的一个极好的模型系统。在正常发育条件下和野生型遗传背景下，果蝇具有两种类型的血细胞，晶细胞和浆细胞。在寄生蜂的侵扰或在某些改变的遗传背景下，第三类血细胞称为片状细胞变得明显。在这里，我们描述了一种新的转录调控模块，畸形基因的片状细胞活性增强子的特性。该转录控制序列似乎在野生型幼虫的所有细胞类型中无活性，包括晶体细胞和浆细胞。然而，在由黄蜂侵染或由特定遗传条件诱导的片状细胞中，增强子被激活，并且其指导报告GFP或DsRed仅在片状细胞中表达。将层状细胞控制区限定为包含AP-1转录因子的必需DNA识别元件的140-bp内含子序列。此外，kayak基因编码的AP-1的dFos亚基的突变导致了强烈的抑制肿瘤幼虫的板层细胞的生产。由于misshapen编码Jun N-末端激酶信号传导途径内的蛋白激酶，其功能是形成活性AP-1复合物，因此片状细胞活性增强子可能充当遗传自调节回路内的转录靶标，其促进免疫激发或遗传受损动物中片状细胞的产生。
Drosophila has emerged as an excellent model system in which to study cellular and genetic aspects of hematopoiesis. Under normal developmental conditions and in wild-type genetic backgrounds, Drosophila possesses two types of blood cells, crystal cells and plasmatocytes. Upon infestation by a parasitic wasp or in certain altered genetic backgrounds, a third hemocyte class called the lamellocyte becomes apparent. Herein we describe the characterization of a novel transcriptional regulatory module, a lamellocyte-active enhancer of the misshapen gene. This transcriptional control sequence appears to be inactive in all cell types of the wild-type larva, including crystal cells and plasmatocytes. However, in lamellocytes induced by wasp infestation or by particular genetic conditions, the enhancer is activated and it directs reporter GFP or DsRed expression exclusively in lamellocytes. The lamellocyte control region was delimited to a 140-bp intronic sequence that contains an essential DNA recognition element for the AP-1 transcription factor. Additionally, mutation of the kayak gene encoding the dFos subunit of AP-1 led to a strong suppression of lamellocyte production in tumorous larvae. As misshapen encodes a protein kinase within the Jun N-terminal kinase signaling pathway that functions to form an active AP-1 complex, the lamellocyte-active enhancer likely serves as a transcriptional target within a genetic auto-regulatory circuit that promotes the production of lamellocytes in immune-challenged or genetically- compromised animals.