Department of Biology and Center for Computational and Integrative Biology, Rutgers, The State University of NJ, Camden, NJ, USA.
Dev Biol. 2013 Mar 1;375(1):45-53. doi: 10.1016/j.ydbio.2012.12.011. Epub 2012 Dec 27.
The Drosophila eggshell is an elaborate structure that is derived from a monolayer of follicular epithelium surrounding the developing oocyte within the female ovary. The bone morphogenetic protein (BMP) signaling pathway is essential for controlling the patterning and morphogenesis of the eggshell. During oogenesis, the roles of patterning and morphogenesis by the BMP type I receptor thickveins (tkv) have been studied extensively. However, signaling through this pathway requires both type I and II receptors, and the latter has yet to be established in oogenesis. We focus on wishful thinking (wit), the Drosophila homolog to the mammalian BMP type II receptor, BMPRII. We found that wit is expressed dynamically in the FCs of D. melanogaster in an evolutionary conserved pattern. The expression patterns are highly correlated with the dynamics of the BMP signaling, which is consistent with our finding that wit is a target of BMP signaling. Furthermore, we established that WIT is necessary for BMP signaling, and loss of WIT is associated with cell autonomous loss of BMP responses. Of importance, we demonstrated that perturbations in WIT led to changes in eggshell morphologies in domains that are patterned by BMP signaling. Previous studies have shown a role for WIT in BMP signaling during neurogenesis; however, our results reveal a role for WIT in epithelial cells' development.
果蝇的卵壳是一种精细的结构，它来源于围绕在雌性卵巢内正在发育的卵母细胞的滤泡上皮细胞的单层。骨形态发生蛋白 (BMP) 信号通路对于控制卵壳的图案形成和形态发生是必不可少的。在卵子发生过程中，BMP 型 I 受体 thickveins (tkv) 的图案形成和形态发生作用已经被广泛研究。然而，该途径的信号传导既需要 I 型和 II 型受体，而后者在卵子发生中尚未建立。我们专注于 wishful thinking (wit)，果蝇的哺乳动物 BMP 型 II 受体 BMPRII 的同源物。我们发现 wit 在 D. melanogaster 的 FCs 中以进化保守的模式动态表达。表达模式与 BMP 信号的动态高度相关，这与我们发现 wit 是 BMP 信号的靶标一致。此外，我们确定 WIT 对于 BMP 信号是必需的，并且 WIT 的缺失与 BMP 反应的细胞自主缺失相关。重要的是，我们证明了 WIT 的扰动导致了由 BMP 信号图案化的卵壳形态的变化。先前的研究表明 WIT 在神经发生过程中的 BMP 信号传导中发挥作用；然而，我们的结果揭示了 WIT 在上皮细胞发育中的作用。
