The Regulation of Chromosome Axis formation in Plant Meiosis

在所有有性繁殖的真核生物中，减数分裂重组对于维持物种的倍性水平和引入遗传变异是必不可少的。两者都需要在减数分裂期间形成的遗传交换（CO）。CO形成的第一步是在DNA中产生双链断裂（DSB）。在许多物种中，产生的DSB数量远远超过最终解决的CO数量;在拟南芥中，大约5%的DSB将成为CO。先前已经阐明了对CO频率和分布的几个控制水平。在许多谷类物种如小麦中，这些对重组的严格控制导致高达50%的遗传信息无法被植物育种者获得。目前还不完全清楚CO的决定是如何做出的，但已知重组机制、染色体轴和减数分裂期间染色体的整体重塑之间的相互作用至关重要。因此，研究染色体轴在减数分裂中的作用是至关重要的，如果我们要了解我们如何操纵减数分裂重组，并允许作物育种家更快地开发新的，改良的品种。通过创新的分子和细胞遗传学技术的结合，这个博士项目旨在进一步了解染色体轴在减数分裂中的作用，以及如何调节单个蛋白质。这将包括研究蛋白质-蛋白质相互作用和转录后修饰，这些修饰可能影响几种核心轴蛋白的调节和作用，以及使用超分辨率显微镜更详细地观察轴。

In all sexually reproducing eukaryotes, meiotic recombination is essential for the maintenance of the ploidy level of the species, and the introduction of genetic variation. Both require genetic crossovers (COs) formed during meiosis. The first step in CO formation is the production of double strand breaks (DSBs) in DNA. In many species, the number of DSBs produced far outweighs the number of COs that eventually resolve; in Arabidopsis thaliana, approximately 5% of DSBs will become COs. Several levels of control on CO frequency and distribution have previously been elucidated. In many cereal species such as Wheat, these stringent controls on recombination result in up to 50% of the genetic information being inaccessible to plant breeders. It is still not fully understood how the decision to make a CO is made, but it is known that the interaction between the recombination machinery, the chromosome axis, and the global remodelling of chromosomes during meiosis is crucial. Investigating the role of the chromosome axis in meiosis is therefore essential if we are to learn how we might manipulate meiotic recombination, and allow crop breeders to more rapidly develop new, improved cultivars. Through a combination of innovative molecular and cytogenetic techniques, this PhD project aims to further our understanding of the role of the chromosome axes in meiosis, and how individual proteins are regulated. This will include investigation of the protein-protein interactions and post-transcriptional modifications that may influence the regulation and role of several core axis proteins, as well as the use of super-resolution microscopy to visualise the axis in greater detail.