Evolutionary Rewiring of a Developmental Gene Regulatory Network

这个项目考察了基因调控的变化如何有助于改变关键的生活史特征，如繁殖力、寿命和特定年龄的死亡率。更多地了解种群的生活史特征是如何变化的，以及它们是如何随着进化时间的推移而变化的，这将有助于阐明基本的生物学过程。该方法涉及对三种海胆在生命周期关键阶段的基因交互作用进行详细分析。这些实验涉及在生命周期的早期阶段操纵具有已知功能的关键调控基因的操作。这些实验操作的影响将被用几种大数据方法来分析，这些方法测量了生命历史后续阶段中数以万计的基因和数千种蛋白质和代谢物的表达。这些结果将揭示关键基因功能的差异如何影响其他基因的功能，从而影响解剖学和健康。这个项目产生的更广泛的影响分为四个方面。首先，用于分析超大基因表达数据集的新计算方法将对基础和应用研究具有广泛的实用价值。其次，大型数据集将免费提供给研究同一物种的其他研究人员。第三，将为培养包括本科生和研究生在内的青年科学家做出重大贡献。最后，这个项目将把PI与北卡罗来纳州科学博物馆合作开发的一个创新的教育推广计划扩展到中学生。这个项目的目标是确定一个定义明确的基因调控网络(GRN)中的进化变化，这些变化有助于海胆从浮游生物(摄食)到磷养性(不摄食)幼虫的生态上的重大转变。该项目正在确定GRN激活和卵子供应的母体变化，并确定GRN亚回路中的合子变化，并评估它们对幼虫特征的影响。卵子能量含量的变化对卵磷脂营养的进化是必不可少的。红蜘蛛的卵比结核杆菌和其他浮游生物的卵要大，并且充满了显著的脂滴。有趣的是，每个鸡蛋的卵黄蛋白原(卵黄蛋白)的数量并没有增加，但甘油三酯和长链脂肪酸的含量要丰富得多。因此，本项目的重点是研究可能导致红毛隐杆藻卵磷脂营养进化的脂类代谢的变化，以确定支持卵磷脂营养发育的特定代谢物，并了解这些变化可能是如何进化的。

This project examines how changes in gene regulation contribute to modifications in key life history traits, such as fecundity, lifespan, and age-specific mortality. Knowing more about how life history traits vary within populations, and how they change over evolutionary time will elucidate fundamental biological processes. The approach involves a detailed analysis of gene interactions during key stages of the life cycle in three species of sea urchins. The experiments involve manipulating the operation of key regulatory genes with known functions during the early phase of the life cycle. The impact of these experimental manipulations will then be assayed using several 'big data' approaches that measure the expression of tens of thousands of genes and thousands of proteins and metabolites during subsequent stages of the life history. These results will reveal how differences in the function of key genes impact the function of other genes, thereby influencing anatomy and health. The broader impacts from this project fall into four areas. First, the novel computational methods for analysis of the very large gene expression datasets will have broad utility for basic and applied research. Second, the large datasets will be made freely available to other researchers who work with the same species. Third, there will be significant contributions to the training young scientists, including undergraduate and graduate students. Finally, this project will extend an innovative educational outreach program to middle school students developed by the PI in partnership with the North Carolina Museum of Science.The objective of this project is to identify evolutionary changes in a well defined gene regulatory network (GRN) that contribute to an ecologically significant shift in developmental mode from planktotrophic (feeding) to lecithotrophic (nonfeeding) larvae in sea urchins. The project is identifing maternal changes underlying GRN activation and egg provisioning, and identify zygotic changes in GRN sub-circuits and assess their impact on larval traits. Changes in the energy content of eggs are essential for the evolution of lecithotrophy. The eggs of H. erythrogramma are larger than those of H. tuberculata and other planktotrophs and are packed with prominent lipid droplets. Interestingly, the amount of vitellogenin (yolk protein) per egg is not elevated, but triglycerides and long chain fatty acids are vastly more abundant. Thus, this project focuses on changes in lipid metabolism that may have contributed to the evolution of lecithotrophy in H. erythrogramma to identify specific metabolites that support lecithotrophic development and to understand how those changes might have evolved.