Bernardi Fabio, Duchi Serena, Cavaliere Valeria, Donati Alessandra, Andrenacci Davide, Gargiulo Giuseppe
Dipartimento di Biologia Evoluzionistica Sperimentale, Università di Bologna, Via Selmi 3, 40126,, Bologna, Italy.
Dev Genes Evol. 2007 Jul;217(7):529-40. doi: 10.1007/s00427-007-0164-1. Epub 2007 Jun 14.
Drosophila vitelline membrane gene VM32E is expressed in the follicle cells of the stage 10 egg chamber and shows a peculiar temporal and spatial expression pattern compared to the other members of the same gene family. Previous work has led us to demonstrate that Decapentaplegic (Dpp) signaling represses the expression of the VM32E gene in the centripetal follicle cells. In this paper, we describe another level of complexity of the VM32E gene expression regulation. Through clonal analyses, we show that the expression of the VM32E gene in the main body follicle cells is modulated by the epidermal growth factor receptor (Egfr) activity. In follicle cell clones expressing a constitutively active form of the Egfr, the VM32E gene is downregulated, while the loss of the Egfr activity upregulates VM32E expression. In addition, we show that the ectopic expression of the Egfr-induced ETS transcription factor PointedP2 (PntP2) affects the expression of the VM32E gene. From these results and our previously published data, it appears that the proper patterning of follicle cells, defined by Dpp and Egfr signaling pathways, controls the VM32E gene expression pattern. This may suggest that a fine tuning of the expression of specific eggshell structural genes could be part of the complex process that leads to a proper eggshell assembly.
果蝇卵黄膜基因VM32E在10期卵室的滤泡细胞中表达，与同一基因家族的其他成员相比，呈现出独特的时空表达模式。先前的研究使我们证明，骨形态发生蛋白（Dpp）信号传导抑制VM32E基因在向心滤泡细胞中的表达。在本文中，我们描述了VM32E基因表达调控的另一个复杂层面。通过克隆分析，我们表明VM32E基因在主体滤泡细胞中的表达受表皮生长因子受体（Egfr）活性的调节。在表达组成型活性形式Egfr的滤泡细胞克隆中，VM32E基因被下调，而Egfr活性的丧失则上调VM32E的表达。此外，我们表明Egfr诱导的ETS转录因子PointedP2（PntP2）的异位表达会影响VM32E基因的表达。从这些结果以及我们之前发表的数据来看，似乎由Dpp和Egfr信号通路定义的滤泡细胞的正确模式控制着VM32E基因的表达模式。这可能表明，特定卵壳结构基因表达的微调可能是导致正确卵壳组装的复杂过程的一部分。
