BTT EAGER: Investigating Genetic, Epigenetic and Environmental Control of Meiotic Recombination using Fluorescent Crossover Reporters in Tomato

大多数作物食品，包括种子、谷物、水果和蔬菜，都是植物有性繁殖的结果。 成功的繁殖需要亲本染色体的相互作用。 植物育种家利用相同类型的染色体相互作用来创造有利性状的新组合。 位于查佩尔山的北卡罗来纳州大学的Copenhaver实验室与他们的合作者，剑桥大学的亨德森实验室先前开发了一种强大的技术，用于检测和量化与芥菜植物相关的模式植物物种中的这些染色体相互作用。 在这个项目中，Copenhaver和亨德森实验室将把这项技术推广到一种商业作物番茄上。 然后，他们将使用该技术来测量遗传，表观遗传和环境因素对影响这些染色体相互作用的数量和基因组分布的影响，以了解驱动植物繁殖的基本生物学机制，并确定加速作物育种的有效途径。 Copenhaver和亨德森实验室将以开放获取的形式发表他们的研究结果，并将他们开发的遗传资源提供给研究人员和工业界的同事。 以前，Copenhaver和亨德森实验室开发了一种直观的方法，用于直接测量拟南芥配子中减数分裂重组的频率。 他们的试验，称为FTL系统，采用了一系列含有编码花粉特异性荧光蛋白的转基因的品系，这些蛋白在四联体（qrt）突变体背景中表达，这使得在高等植物中进行四联体分析成为可能。 在这个项目中，他们将把FTL系统翻译成Solanum lycopersicum（番茄）。 使用番茄FTL系统，他们将测试CRISPR/Cas9诱导的recq4解旋酶同源物突变是否会导致全基因组超重组。 他们还将测试CRISPR/Cas9诱导的介导表观遗传机制（如DNA甲基化和小RNA生物发生）的基因突变是否可以改变具有不同染色质环境（如着丝粒）的特定染色体结构域周围的重组频率。 先前在拟南芥中的工作表明，暴露于高温和低温可以显着调节重组频率。 Copenhaver和亨德森实验室将测试类似的环境操作是否可以改变S.番茄 该项目将为两名博士后研究员提供培训，并为Copenhaver和亨德森实验室的本科生提供独立的研究经验。 研究结果将以开放获取的形式发表，所有的遗传资源将提供给研究和工业界的同事。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Most crop foods, including seeds, grains, fruit and vegetables, are the result of plant sexual reproduction. Successful reproduction requires the interaction of parental chromosomes. The same kind of chromosomal interactions are used by plant breeders to create new combinations of favorable traits. The Copenhaver lab at The University of North Carolina at Chapel Hill together with their collaborators, the Henderson lab from the University of Cambridge previously developed a powerful technique for detecting and quantifying these chromosome interactions in a model plant species related to the mustard plant. In this project the Copenhaver and Henderson labs will extend that technology into a commercial crop species tomato. They will then use that technology to measure the effects of genetic, epigenetic and environmental factors on influencing the number and genomic distribution of these chromosome interactions in order to understand the fundamental biological mechanism that drive plant reproduction, as well as to identify fruitful avenues for accelerating crop breeding. The Copenhaver and Henderson labs will publish their findings in open-access formats, and make the genetic resources they develop available to researchers and industrial colleagues. Previously, the Copenhaver and Henderson labs developed a visual assay for measuring meiotic recombination frequencies directly in the gametes of Arabidopsis thaliana. They assay, called the FTL system, employs a collection of lines harboring transgenes encoding pollen-specific fluorescent proteins expressed in the quartet (qrt) mutant background, which enable tetrad analysis in a higher plant. In this project they will translate the FTL system into Solanum lycopersicum (tomato). Using the tomato FTL system they will test whether CRISPR/Cas9 induced mutations in recq4 helicase homologs result in genome wide hyper-recombination. They will also test whether CRISPR/Cas9 induced mutations in genes that mediate epigenetic mechanisms such as DNA methylation and small RNA biogenesis can alter recombination frequencies around specific chromosomal domains with distinct chromatin environments such as centromeres. Prior work in Arabidopsis, suggests that exposure to high and low temperatures can significantly modulate recombination frequencies. The Copenhaver and Henderson lab will test whether similar environmental manipulation can alter recombination frequencies in S. lycopersicum. The project will provide training for two postdoctoral fellows as well as independent research experiences for undergraduates in both the Copenhaver and Henderson lab. The research findings will be published in open-access formats, and all genetic resources will be made available to both research and industrial colleagues.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.