TRANSLATIONAL CONTROL DURING THE DEVELOPMENT OF VOLVOX

描述（改编自申请人摘要）：本提案是 与殖民地绿色团藻的翻译控制有关 卡特里。 在这个阶段，发育的初始阶段（胚胎发生） 发生在光下，但大多数细胞分裂在卵裂阶段 发生在随后的黑暗时期。 卵裂后，新形成的 幼蚁群反转并进入休眠期，直到下一次光照 期 分化的最后阶段迅速完成 重新照明。 大多数蛋白质在黑暗中无法合成 阶段，尽管存在正常的mRNA群体。 因此 发展的最后阶段似乎与全球 翻译抑制 研究转译的机制 镇压，研究人员建议隔离和表征 翻译抑制缺陷的突变体。 这些变种人将会 用于翻译控制的遗传和生物化学研究 通路 在第二个具体目标中，他将检验以下假设： 翻译抑制涉及磷酸化状态的改变 一个或多个翻译因子，使用麦胚抗体 翻译因素的特点是在卡伦布朗宁的实验室在 德克萨斯大学 第三个目标涉及额外的实验 旨在研究其他潜在的监管机制，包括 蛋白质与mRNA的5'前导区的结合， 多聚腺苷酸化的变化。 最后，消减cDNA文库将 构建的目的是分离特异性翻译的mRNA， 光明还是黑暗 这些克隆将用于结合和 多聚腺苷酸化的研究，并可能为未来的实验提供基础 设计通过制造嵌合基因定位顺式调节元件 融合

DESCRIPTION (Adapted from the applicant's abstract): This proposal is concerned with translational control in the colonial green alga Volvox carteri. In this alga, the initial phases of development (embryogenesis) occur in the light, but most of the cell divisions in the cleavage stage occur during a subsequent dark period. After cleavage, the newly formed juvenile colony inverts and enters a resting phase until the next light period. The final phases of differentiation are then completed rapidly upon reillumination. Most proteins are not synthesized during the dark phase, despite the presence of a normal population of mRNAs. Thus the final stages of development appear to be synchronized by global translational repression. To study the mechanism of translational repression, the investigator proposes to isolated and characterize mutants defective in translational repression. These mutants will be used in genetic and biochemical studies of the translational control pathway. In a second specific aim, he will test the hypothesis that translational repression involves a change in the phosphorylation state of one or more translation factors, using antibodies to wheat germ translation factors characterized in Karen Browning's laboratory at the University of Texas. A third aim deals with additional experiments designed to investigate other potential regulatory mechanisms, including binding of proteins to the 5' leader regions of mRNAs and possible changes in polyadenylation. Finally, subtractive cDNA libraries will be constructed in an effort to isolate mRNAs specifically translated in the light or the dark. These clones will be useful in the binding and polyadenylation studies and may provide a basis for future experiments designed to localize cis regulatory elements by making chimeric gene fusions.