meiTALENs: Directing crossover recombination with meiotic TAL nucleases

meiTALENs：用减数分裂 TAL 核酸酶指导交叉重组

• 批准号: BB/L006847/1
• 负责人: Ian Henderson
• 金额: $ 53.22万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FL006847%2F1
• 关键词: meiTALENs; Directing; crossover; recombination; meiotic

There is a critical need to improve crop yields to provide food security for the growing human population. Harnessing the genetic variation present in crops and their wild relatives is critical for crop improvement. Most crops have passed through domestication bottlenecks and so contain a fraction of wild genetic diversity. Crossing can therefore reintroduce useful variation from wild strains, for example in disease and stress resistance and increase yield. This process is dependent on recombination and independent chromosome segregation that occurs during meiosis. Meiotic recombination can produce crossovers between chromosomes and generation of novel combinations of genetic variation. Where crossovers occur in the genome is non-random, which can impose a limitation on breeding. For example, many important crops such as maize, wheat, barley and tomato have very skewed crossover patterns, with the majority of events occurring towards the end of the chromosomes. Therefore, useful variation located in the centre of crop chromosomes can be difficult for breeders to fully utilise. In the proposed work we will develop synthetic tools that will allow scientists and breeders to direct crossover recombination to specific sites in the genome. This will be done by fusing programmable DNA binding domains to nucleases and expressing them during the meiotic sexual cell division. This will drive breaks in the DNA at target sites, which will then be repaired as crossovers via the specialized machinery present during meiosis. We will perform this work as a proof-of-principle in the model species Arabidopsis thaliana, which has extensive genetic and genomic resources that will ensure rapid progress and demonstration of functionality. For example, we have developed fluorescent systems that allow us to score 100,000s of meiosis in 10-15 minutes. As the recombination machinery is highly conserved between plants our understanding will be directly applicable to crop species. This work will take advantage of cutting-edge synthetic biology to manipulate the core process of meiotic recombination, with direct impact for crop improvement.

迫切需要提高作物产量，为不断增长的人口提供粮食安全。利用农作物及其野生近亲的遗传变异对作物改良至关重要。大多数作物都经历了驯化瓶颈，因此包含了一小部分野生遗传多样性。因此，杂交可以重新引入野生品系的有用变异，例如在抗病和抗逆性方面，并提高产量。这一过程依赖于减数分裂过程中发生的重组和独立的染色体分离。减数分裂重组可以在染色体之间产生交叉，并产生新的遗传变异组合。基因组中发生交叉的地方是非随机的，这可能会对繁殖造成限制。例如，许多重要的作物，如玉米、小麦、大麦和番茄都有非常扭曲的交叉模式，大多数事件发生在染色体末端。因此，位于作物染色体中心的有用变异对育种者来说可能很难充分利用。在拟议的工作中，我们将开发合成工具，使科学家和育种者能够将交叉重组定向到基因组中的特定位置。这将通过将可编程DNA结合域与核酸酶融合并在减数分裂的有性细胞分裂中表达它们来完成。这将在目标位置驱动DNA断裂，然后通过减数分裂过程中存在的特殊机械将其修复为交叉。我们将在模式物种拟南芥中进行这项工作作为原则证明，该模式物种拥有丰富的遗传和基因组资源，将确保快速进步和功能展示。例如，我们已经开发了荧光系统，可以在10-15分钟内完成100,000次减数分裂。由于重组机制在植物之间是高度保守的，我们的理解将直接适用于作物物种。这项工作将利用前沿的合成生物学来操纵减数分裂重组的核心过程，对作物改良产生直接影响。

项目成果

Recombination Rate Heterogeneity within Arabidopsis Disease Resistance Genes.

拟南芥抗病基因重组率异质性

• DOI: 10.1371/journal.pgen.1006179
• 发表时间: 2016-07
• 期刊: PLoS genetics
• 影响因子: 4.5
• 作者: Choi K;Reinhard C;Serra H;Ziolkowski PA;Underwood CJ;Zhao X;Hardcastle TJ;Yelina NE;Griffin C;Jackson M;Mézard C;McVean G;Copenhaver GP;Henderson IR
• 通讯作者: Henderson IR

Nucleosomes and DNA methylation shape meiotic DSB frequency in Arabidopsis thaliana transposons and gene regulatory regions.

核小体和 DNA 甲基化塑造拟南芥转座子和基因调控区减数分裂 DSB 频率。

• DOI: 10.17863/cam.23795
• 发表时间: 2018
• 作者: Choi K

REC8-cohesin, chromatin and transcription orchestrate meiotic recombination in the Arabidopsis genome

REC8-粘连蛋白、染色质和转录协调拟南芥基因组中的减数分裂重组

• DOI: 10.1101/512400
• 发表时间: 2019
• 作者: Lambing C

Massive crossover elevation via combination of HEI10 and recq4a recq4b during Arabidopsis meiosis.

在拟南芥减数分裂过程中，HEI10 和 recq4a、recq4b 的组合导致大量交叉升高。

• DOI: 10.17863/cam.25792
• 发表时间: 2018
• 作者: Henderson I