Chromatin and recombination landscapes in the hexaploid wheat genome.

六倍体小麦基因组中的染色质和重组景观。

• 批准号: 2120139
• 金额: --
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2120139
• 关键词: Chromatin; recombination; landscapes; hexaploid; wheat

Meiotic recombination creates genetic diversity in the progeny of sexually reproducing species.For example, reciprocal exchange between homologous chromosomes (known as crossover)creates novel combinations of genetic variation. The variation-generating processes actingduring meiosis remain a major tool for crop improvement, whereby useful characteristics fromdifferent backgrounds can be combined.Bread wheat is a major crop in the UK and globally, where meiotic recombination duringbreeding remains an essential tool for variety improvement. However, the wheat genome isextremely large (17 gigabases) and shows highly skewed recombination distributions, with mostcrossovers occurring in the distal regions of the chromosomes. This severely limits the ability ofbreeders to utilise variation located in the central regions of the chromosomes. Therefore,developing tools and technologies to control recombination in wheat has direct relevance forfood security.In this project the student will use chromatin immunoprecipitation (ChIP) followed by highthroughput sequencing to profile the distribution of euchromatic and heterochromatic chromatinmodifications throughout the wheat genome. These distributions will be related to highresolutiongenetic maps generated by KWS and genotypes that differ in their genetic maplengths. These experiments will be conducted in backgrounds of interest to KWS and thestudent will identify chromatin patterns that correlate with altered frequencies and patterns ofrecombination. The recent public release of a high quality reference genome assembly for wheatmakes this project feasible and timely.New reverse genetic resources (e.g. TILLING, CRISPR-Cas9) are available that allow genes ofinterest to be disrupted in bread wheat. To functionally investigate the role of chromatin onrecombination the student will isolate mutations in epigenetic regulators. These mutants will beprofiled using ChIP-seq in order to characterise how chromatin is altered genome-wide. Finally,these mutants will be used to measure effects on number and distribution of recombinationevents during meiosis.This project will provide the student with advanced training in wheat genetics and genomics.They will generate data of basic importance for understanding wheat genome function andevolution. They will gain experience in wheat genetics relevant to both academic and industrialscientific contexts.

减数分裂重组在有性繁殖物种的后代中创造了遗传多样性。例如，同源染色体之间的相互交换（称为交叉）创造了遗传变异的新组合。减数分裂过程中的变异产生过程仍然是作物改良的主要工具，从而可以将来自不同背景的有用特性结合起来。面包小麦是英国和全球的主要作物，其中育种过程中的减数分裂重组仍然是品种改良的重要工具。然而，小麦基因组非常大（17千兆碱基），并显示出高度偏斜的重组分布，大多数交叉发生在染色体的远端区域。这严重限制了育种者利用位于染色体中心区域的变异的能力。因此，开发控制小麦重组的工具和技术对粮食安全有着直接的意义。在这个项目中，学生将使用染色质免疫沉淀（ChIP），然后进行高通量测序，以分析整个小麦基因组中常染色质和异染色质染色质修饰的分布。这些分布将与KWS生成的高分辨率遗传图谱和遗传图谱中不同的基因型有关。这些实验将在KWS感兴趣的背景下进行，学生将识别与重组频率和模式改变相关的染色质模式。最近公开发布的小麦高质量参考基因组组装使该项目变得可行和及时。新的反向遗传资源（例如TILLING，CRISPR-Cas9）可用于破坏面包小麦中的感兴趣基因。为了从功能上研究染色质在重组中的作用，学生将分离表观遗传调节因子中的突变。这些突变体将使用ChIP-seq进行分析，以确定染色质是如何在全基因组范围内改变的。最后，这些突变体将被用来测量减数分裂过程中重组事件的数量和分布的影响。这个项目将为学生提供小麦遗传学和基因组学的高级培训。他们将产生对理解小麦基因组功能和进化至关重要的数据。他们将获得与学术和工业科学背景相关的小麦遗传学经验。