The Role of Oogenesis in Speciation

项目摘要 地球上所有的生物多样性都是通过物种形成过程产生的。当物种形成研究集中在 关于物种间生殖障碍的起源，这项工作的结果将为研究 不孕不育是一个重要的生殖健康问题。虽然配子发生是一个合乎逻辑的发展过程 关于生殖隔离的研究，几乎所有的研究都集中在雄性配子发生上，很少或根本没有 研究卵子发生。拟议中的研究假设环境压力加速了这种积累。 通过它对卵子发生的影响来研究遗传分化，得出生殖和生殖之间的联系 环境健康。例如，环境压力已被证明会导致自发性反复发作。 堕胎，使这项工作与公共卫生相关。环境压力有四个主要后果 卵子发生-转座元件、结构变异、减数分裂重组率和基因调控- 已被证明对物种形成研究很重要。通过增加遗传差异，卵子发生 促进差异暴露的物种之间的物种形成。这项提案主要集中在 重组，同时朝着整合其他成果迈出重要一步。之前的研究已经 表明重组率比核苷酸分歧进化得更快。再加上证据 重组率对环境很敏感，这表明环境可能是一个主要驱动因素 通过重组实现局部适应。这一建议利用了实验操作的易用性 研究果蝇对环境敏感的卵子发生、积累新基因之间的联系 变异，以及随后的物种分化。首先，将物种内的卵子发生与杂交进行比较。 在对照和应激条件下，研究基因表达、染色质构象、生物体 压力反应和重组的衡量标准。通过靶向与以下因素相关的分子通路 转座元件沉默和DNA修复，这项工作可以间接地告知积累这些新的 遗传变异，回答了进化生物学中关于内部和内部来源的一个关键问题 物种变异。第二，因为杂交卵子发生的差异可以归因于生殖 不相容影响健康，这项工作将调查健康和重组之间的关系 塑性直接与三个独特的实验应力处理。突变标记将被用来比较 重组，借助一种新型的高通量表型机器人。已知的野生型股票 对选定的压力源敏感或容忍将成为目标。这项工作的一大创新将是调查 直接进行组织压力反应，以比较不同治疗方法的适合度。从这两家公司收集的数据 在更广泛的复合率可塑性机制的研究中，这些问题将是至关重要的 即使在这一领域进行了一个世纪的研究之后，它仍然是一个谜。在五年内，拟议的工作将回答 这不仅有助于解决物种形成中的关键问题，同时也填补了卵子发生在物种形成中的重要性这一重大空白。

Project Summary All biodiversity on earth is generated through the process of speciation. While speciation research is focused on the origins of reproductive barriers between species, the results of this work will inform the study of infertility, an important reproductive health concern. Though gametogenesis is a logical developmental process to study in regard to reproductive isolation, nearly all research focuses on male gametogenesis, with little to no work on oogenesis. The proposed research hypothesizes that environmental stress hastens the accumulation of genetic divergence through its impact on oogenesis, drawing connections between reproductive and environmental health. For example, environmental stress has been shown to cause recurrent spontaneous abortion, making this work relevant to public health. There are four key outcomes of environmental stress on oogenesis – transposable elements, structural variants, meiotic recombination rates, and gene regulation – that have been shown to be important to the study of speciation. By increasing genetic differences, oogenesis facilitates speciation between species that are differentially exposed. This proposal focuses primarily on recombination, while taking an important step towards integrating other outcomes. Previous research has shown that recombination rates evolve more rapidly than nucleotide divergence. This coupled with evidence that recombination rates are environmentally sensitive, suggests that the environment could be a major driver of local adaptation through recombination. This proposal leverages the ease of experimental manipulation in fruit flies to study the link between environmental sensitivity of oogenesis, the accumulation of novel genetic variation, and subsequent species divergence. First, within species oogenesis will be compared to hybrids under control and stress conditions investigating gene expression, chromatin conformation, organismal measures of stress response, and recombination. By targeting molecular pathways associated with transposable element silencing and DNA repair, this work can indirectly inform the accumulation of these novel genetic variants, answering a key question in evolutionary biology regarding sources of intra- and inter- species variation. Second, because differences in hybrid oogenesis could be attributed to reproductive incompatibilities impacting fitness, this work will investigate the relationship between fitness and recombination plasticity directly with three unique experimental stress treatments. Mutant markers will be used to compare recombination, with the aid of a novel high-throughput phenotyping robot. Wild type stocks known to be either sensitive or tolerant to selected stressors will be targeted. A major innovation of this work will be to investigate organismal stress response directly to compare fitness across treatments. The data collected from these two questions will be critical in the broader investigation of mechanisms of recombination rate plasticity, which remains a mystery even after a century of research in this area. In five years, the proposed work will answer crucial questions in speciation, while also filling a major gap of the importance of oogenesis in speciation.