Inductive Mechanisms in Arthropod Germ Line Specification

节肢动物种系规范中的诱导机制

• 批准号: 1257217
• 负责人: Cassandra Extavour
• 金额: $ 49万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-01-15 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1257217&HistoricalAwards=false
• 关键词: Inductive; Mechanisms; Arthropod; Germ; Line

Eggs and sperm are made by special cells called germ cells. Germ cells are critical not only to organismal survival but also to species survival and evolution, because they are the only cell type capable of producing the next generation. It is therefore critical to understand the genetic and molecular mechanisms that make sure germ cells are specified in embryos. Studies using traditional model organisms such as mice and fruit flies have suggested that some animals use an 'inheritance' mechanism to specify germ cells, whereby germ cell-determining substances are placed into developing eggs before embryonic development begins. In other animals, an 'inductive' mechanism operates, whereby cells exchange signals to determine which cells should become germ cells. For decades it was thought that most animals used the inheritance mechanism, and that mammals were exceptional in using the inductive mechanism. Prior research by the PI challenged this assumption by discovering the first example of a non-mammalian animal that uses the inheritance mechanism. To make this discovery, they studied germ cells in a cricket called Gryllus bimaculatus. The current project will extend this novel finding by determining whether the signals used to specify germ cells are actually the same in both mammals and crickets. If this proves to be the case, it could mean that the same signaling mechanism was used to specify germ cells in a last common ancestor of all animals. This work has high transformative potential, as it will have a radical impact on our understanding of how germ cells are specified in diverse animals, and how the mechanisms used to specify germ cells evolved. The current project will also develop new educational tools that use science fiction films to engage both the general public and university undergraduates in the study of developmental biology and genetics.

卵子和精子是由称为生殖细胞的特殊细胞产生的。生殖细胞不仅对生物体的生存至关重要，而且对物种的生存和进化也至关重要，因为它们是唯一能够产生下一代的细胞类型。因此，了解确保胚胎中指定生殖细胞的遗传和分子机制至关重要。使用传统模式生物如小鼠和果蝇的研究表明，一些动物使用“遗传”机制来指定生殖细胞，即在胚胎发育开始之前将生殖细胞决定物质放入发育中的卵子中。在其他动物中，一种“诱导”机制起作用，细胞通过交换信号来决定哪些细胞应该成为生殖细胞。几十年来，人们一直认为大多数动物都使用遗传机制，而哺乳动物在使用诱导机制方面是例外。PI之前的研究通过发现第一个使用遗传机制的非哺乳动物的例子来挑战这一假设。为了做出这一发现，他们研究了一种名为Gryllus bimaculatus的蟋蟀的生殖细胞。目前的项目将通过确定用于指定生殖细胞的信号在哺乳动物和蟋蟀中是否实际上是相同的来扩展这一新发现。如果这被证明是事实，这可能意味着相同的信号机制被用来指定所有动物最后一个共同祖先的生殖细胞。这项工作具有很高的变革潜力，因为它将对我们理解生殖细胞如何在不同动物中指定以及用于指定生殖细胞的机制如何进化产生根本性的影响。目前的项目还将开发新的教育工具，利用科幻电影吸引公众和大学本科生参与发育生物学和遗传学的研究。