mRNA Translation and Germline Evolution in Caenorhabditis

秀丽隐杆线虫的 mRNA 翻译和种系进化

• 批准号: 1355119
• 负责人: Eric Haag
• 金额: $ 64.5万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-15 至 2019-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1355119&HistoricalAwards=false
• 关键词: mRNA; Translation; Germline; Evolution; Caenorhabditis

One of the grand challenges of evolutionary biology is to understand how new anatomical features emerge without disrupting the overall coherence of development. Because many genes that control development are widely conserved, the process must blend both ancient components and new features, such as species-specific genes or regulatory connections between genes. This research examines an ecologically important novelty that has evolved repeatedly in Caenorhabditis nematodes--self-fertile hermaphroditism. A key step in the evolution of self-fertility was the ability of otherwise female worms to produce a limited number of sperm, which turned them into hermaphrodites. Hermaphrodite sperm production is regulated by messenger RNA-binding proteins (RBPs) present in the germ cells (the precursors of gametes). One of these RBPs, GLD-1, is an ancient, slow-evolving protein that regulates hundreds of target mRNAs. GLD-1 was coopted into hermaphrodite germ line sex determination independently in two different species, C. elegans and C. briggsae. However, in C. elegans GLD-1 promotes sperm fate, whereas in C. briggsae GLD-1 represses it. This paradox is explained by the species-specific evolution of GLD-1 protein cofactors and by changes in the sequences of the mRNA molecules that GLD-1 binds. This project will work with several Caenorhabditis species to systematically examine how both cofactors and mRNA sequence changes alter the context of GLD-1 activity to allow the emergence of a new reproductive strategy. More generally, this research will help reveal how old molecules can take on new roles, thereby linking evolution at the molecular and organismal scales of biological organization. We will use this project to help local high school teachers understand the excitment of scientific research so they can convey these lessons to their classes.

进化生物学的巨大挑战之一是了解新的解剖特征如何在不破坏发展的整体连贯性的情况下出现。由于许多控制发育的基因是广泛保守的，因此该过程必须融合古代组成部分和新特征，例如特定于物种的基因或基因之间的调节连接。这项研究研究了一种在生态上重要的新颖性，该新颖性在线虫炎 - 自我的雌雄同体雌雄同体中反复演变。自我育的发展的关键步骤是否则雌性蠕虫产生有限数量的精子的能力将其变成了雌雄同体。雌雄同体的精子的产生受生殖细胞中存在（配子的前体）中的信使RNA结合蛋白（RBP）调节。这些RBP之一GLD-1是一种古老的慢速蛋白质，可调节数百个靶标mRNA。 GLD-1在两种不同的秀丽隐杆线虫和briggsae中独立地掌握了雌雄同体的细菌性别确定。然而，在秀丽隐杆线虫中，gld-1促进了精子命运，而在briggsae gld-1中，gld-1抑制它。 GLD-1蛋白辅因子的物种特异性演化以及GLD-1结合的mRNA分子的序列的变化来解释这种悖论。该项目将与几种Caenorhabditis物种合作，以系统地检查辅助因子和mRNA序列变化如何改变GLD-1活性的背景，以允许出现新的生殖策略。更普遍地，这项研究将有助于揭示旧分子如何扮演新角色，从而将生物组织分子和生物尺度的进化联系起来。 我们将使用这个项目来帮助当地的高中教师了解科学研究的兴奋，以便他们可以将这些课程传达给他们的课程。