MAD DURING RETINAL DEVELOPMENT AND DROSOPHILA

TGF-β信号转导通路在细胞的形成中起重要作用 在秀丽隐杆线虫等多种生物的发育过程中， 黑腹果蝇、老鼠和人类。 Smad蛋白的功能是 TGF-β信号转导通路中的转录因子 并与人类癌症有关， 强调其在发展进程中的重要性。 关于Smad 随着Mad基因的发现， 其在果蝇中TGF-β同源物dpp的下游起作用。 对Mad中功能缺失突变的研究表明， 是果蝇成年视网膜形成所必需的。因为 果蝇的成年视网膜适合研究， 广泛的特点，它是理想的阐明机制， Mad和DPP途径在发育过程中发挥作用。 研究 组成性激活的Mad蛋白对视网膜色素变性的影响 发展将导致更好地了解疯狂的作用， 视网膜发育过程中的DPP途径。 利用Mad中的突变， 分析DPP途径与其他基因之间的相互作用 在果蝇和果蝇的视网膜发育早期， 脊椎动物中，将阐明DPP与这些基因之间的关系。 最后，识别能够与Mad相互作用的基因将揭示 DPP信号转导的机制以及其他基因 参与视网膜发育。

TGF-Beta signal transduction pathways play important roles in patterning during development of organisms as diverse as Caenorhabditis elegans, Drosophila melanogaster, mice, and humans. Smad proteins function as transcription factors in TGF-Beta signal transduction pathways in all of these organisms, and have been implicated in cancer in humans, underscoring their importance in developmental processes. The Smad protein family was first identified with the discovery of the Mad gene, which functions downstream of the TGF-Beta homologue dpp in Drosophila. Study of loss-of-function mutations in Mad have revealed that it is required for patterning of the adult retina in Drosophila. Because the Drosophila adult retina is amenable to study and has already been extensively characterized, it is ideal for elucidating the mechanisms by which Mad and the dpp pathway function during development. Studying the effects of a constitutively activated Mad protein on retinal development will lead to a greater understanding of the role of Mad and the dpp pathway during retinal development. Using mutations in Mad to analyze the interactions between the dpp pathway and other genes apparently involved early in retinal development in both Drosophila and vertebrates, will clarify the relationships between dpp and these genes. Finally, identifying genes able to interact with Mad will reveal the mechanisms of dpp signal transduction, as well as additional genes involved in retinal development.