A means to the ends - analysis of telomere function and dynamics in plant meiosis

减数分裂过程中染色体的重组和分配是真核生物产生遗传多样性的关键机制。同源染色体的正确分离需要它们在减数分裂前期Ⅰ配对和联会。大多数来自动物和酵母的工作表明，端粒在减数分裂中对染色体的精细行为起着重要作用。端粒形成所谓的端粒花束，并被证明可以驱动染色体快速移动，促进配对。然而，鉴于端粒的多样性，动物和酵母的知识不能简单地翻译到其他物种，我们对染色体编排的分子基础，特别是端粒在植物中的作用知之甚少。这种知识的缺乏也限制了生物技术的应用，例如控制配对，从而控制来自目前使用的育种系的野生亲缘的等位基因的渐渗，以及产生新的多倍体作物。在这里，我们将利用我们在端粒生物学和减数分裂活细胞成像的综合专业知识，以产生标记的端粒在体内标记，并使用它们来进行详细的时空分析的端粒动态和染色体运动在拟南芥。我们将通过使用一个含有极短端粒的独特细胞系，进一步从功能上评估端粒在减数分裂中的作用。作为这些方法的补充，我们将确定植物shelterin复合物的组成部分，这将为未来破译植物染色体配对的分子机制铺平道路。

Chromosome recombination and their assortment during meiosis are key mechanisms for generating genetic diversity in eukaryotic organisms. Faithfull segregation of homologous chromosomes requires their pairing and synapsis in meiotic prophase I. Work mostly from animals and yeast has indicated that telomeres play an important role for the elaborated chromosome behavior in meiosis. Telomeres form a so-called telomere bouquet and were shown to drive rapid chromosome movements that facilitate pairing. However, given the diversity of telomeres, the knowledge from animals and yeast cannot simply be translated into other species and we only know very little about the molecular underpinnings of chromosome choreography and in particular the role of telomeres in plants. This lack of knowledge also limits biotechnological applications, e.g. the control of pairing and hence introgression of alleles from wild relatives of currently used breeding lines as well as the generation of new polyploid crops. Here, we will take advantage of our combined expertise in telomere biology and live cell imaging of meiosis to generate markers for in vivo labeling of telomeres and use them to perform detailed spatiotemporal analyses of telomere dynamics and chromosome movements in Arabidopsis thaliana. We will further functionally assess the role of telomeres in meiosis by using a unique line that harbors extremely short telomeres. Complementing these approaches, we will identify components of the plant shelterin complex, which will pave way for future deciphering of the molecular machinery underlying chromosome pairing in plants.