Do Parental Conflict and Genomic Imprinting Cause Hybrid Lethality in Mimulus?

描述（由申请人提供）：拟议的研究将检查父母和后代之间的能源和资源冲突在多大程度上推动植物物种多样化。具体来说，它将调查种子致死，这是一个常见的结果，在植物杂交，结果从母亲和父亲的等位基因之间的相互作用，营养资源的分配，以发展中的胚胎冲突。这项工作将集中在两个物种的monkeyflower，Mimulus nudatus和Mimulus guttatus，这是没有发现在野生杂交，只能在温室中进行杂交困难。这项工作将利用这些物种中的每一个与第三个Mimulus物种的交叉相容性，将一个物种的基因组中的基因引入另一个物种的基因组并观察效果。这项研究将采用尖端的基因组测序技术和新的基因组数据统计分析，以确定和物理映射到染色体上的候选基因，导致种子在相关物种之间的杂交致死。拟议的实验将测试，使用基因插入技术，这些基因在功能失调的种子发育中发挥什么样的因果作用。最后，这个项目将研究是否母本和父本的基因拷贝在种子中以不同的水平表达，以及异常表达模式是否与种子致死性相关。拟议的工作是一个重要的贡献，我们了解的遗传机制的过程中，物种的分歧一般。此外，它将使我们能够表征导致植物间杂交失败的基因的功能和多样性。这项研究对于我们理解植物多样化的驱动因素和尝试从通常不能杂交的现有品系中创造新的作物品种都具有相关性。 公共卫生相关性：哺乳动物和植物中的基因组印记代表了趋同进化的一个壮观案例，这是由于发育中的胚胎和母亲之间的物理连接的共同特征，并且具有多个平行作用的相似蛋白质组参与了这两个组。在人类中，发育过程中基因组印记正常过程的中断与神经系统疾病、心血管疾病和代谢紊乱（包括肥胖）有关。这项研究将增加我们对胚胎发育中涉及的基因组印记机制的理解，并可能导致更好的工具来诊断和治疗由印记功能障碍引起的人类疾病。

DESCRIPTION (provided by applicant): The proposed research will examine the extent to which conflict over energy and resources between parent and offspring drives species diversification in plants. Specifically it will investigate whether seed lethality, which is a common outcome of hybridization in plants, results from conflicting interactions between maternal and paternal alleles over the allocation of nutritional resources to the developing embryo. This work will focus on two species of monkeyflower, Mimulus nudatus and Mimulus guttatus, which are not found to hybridize in the wild and can only be crossed with difficulty in the greenhouse. The work will take advantage of the cross compatibility that each of these species has to a third Mimulus species to introduce genes from the genome of one species into the genome of the other and observe the effect. This research will employ cutting-edge genomic sequencing techniques and novel statistical analyses of genomic data to identify and physically map candidate genes onto chromosomes that cause seed lethality in crosses between related species. The proposed experiments will test, using gene insertion techniques, what causal role these genes play in dysfunctional seed development. Finally, this project will examine whether maternal and paternal copies of genes are expressed at different levels in seeds, and whether abnormal expression patterns correlate with seed lethality. The proposed work represents an important contribution to our understanding of the genetic mechanisms underlying the process of species divergence in general. Moreover, it will enable us to characterize the function and diversity of genes causing failed hybridization between plants. This research has relevance both for our understanding of the factors driving plant diversification and for attempts to create new crop varieties from existing lines that usually cannot hybridize. PUBLIC HEALTH RELEVANCE: Genomic imprinting in mammals and plants represents a spectacular case of convergent evolution due to the shared trait of a physical connection between the developing embryo and the mother, and similar protein groups with multiple parallel actions are involved in both groups. In humans, disruptions in the normal process of genomic imprinting during development have been linked to neurological disorders, cardiovascular disease and metabolic disorders, including obesity. This research will increase our understanding of the genomic imprinting mechanisms involved in embryonic development and potentially lead to better tools for diagnosing and treating human diseases that arise from imprinting malfunction.