一种基于阵列的比较基因组杂交平台, 有效检测快中子诱导的苜蓿蒺藜突变体的拷贝数变化
Summary
该协议提供了实验步骤和有关试剂、设备和分析工具的信息, 这些研究人员有兴趣执行整个基因组阵列的比较基因组杂交 (计算全息) 对拷贝数变化的分析植物.
Abstract
突变体是基因功能研究的宝贵的遗传资源。为了产生突变体集合, 可利用三种诱变, 包括生物如 T-脱氧核糖核酸或转, 化学物质如甲基磺酸乙酯 (EMS), 或物理如电离辐射。所观察到的突变类型因所使用的诱变而异。对于电离辐射诱发突变体, 突变包括删除, 重复, 或重排。虽然 T-DNA 或 transposon-based 诱变仅限于易受转化的物种, 但化学或物理诱变可应用于种类繁多的物种。然而, 从化学或物理诱变衍生的突变的定性传统上依赖于地图的克隆方法, 这是劳动密集型和耗时。在这里, 我们表明, 一个高密度基因组阵列的比较基因组杂交 (aCGH) 平台可用于有效地检测和表征拷贝数变异 (cnv) 的突变从快中子轰击 (FNB) 突变中获得的苜蓿蒺藜, 豆科植物。整个基因组序列分析显示, 在m 蒺藜中有超过5万基因或基因模型。目前, FNB 诱发突变体的m. 蒺藜是从超过 15万 M1 线, 代表了宝贵的基因资源的功能研究的基因组。这里描述的 aCGH 平台是一个有效的工具, 用于表征 FNB 诱导突变体在m 蒺藜。
Introduction
豆类 (豆科) 是第三大家族的开花植物, 与许多经济上重要的物种, 如大豆 (甘氨酸 max) 和苜蓿 (苜蓿)。豆科植物可以与固氮土壤细菌相互作用, 通常称为根瘤菌来发展根结节, 将大气氮减少到氨供寄主植物使用。因此, 种植豆类作物需要很少的氮肥投入, 从而有助于可持续农业。豆类作物生产的叶子和种子的高蛋白含量, 作为优良的饲料和谷物作物。然而, 种植豆科植物通常有复杂的基因组结构, 使功能研究的基因发挥关键作用在豆类特定的过程繁琐。苜蓿蒺藜已被广泛采用为豆科植物的模型, 主要是因为 (1) 它有一个相对较小的单倍体基因组大小 (~ 550) 的二倍体基因组;(2) 植物可稳定转化为基因功能研究;和 (3) 它与紫花苜蓿 (m), 牧草皇后, 和许多其他经济重要的农作物的转化研究密切相关。最近, m 蒺藜cv Jemalong A17 的基因组序列已被释放12。对基因组的诠释显示, 基因组中有超过5万预测基因或基因模型。要确定m 蒺藜基因组中大多数基因的功能是一项具有挑战性的任务。为了促进基因的功能研究, 在 15万 M1线范围内, 利用快中子轰击 (FNB) 诱变, 在m. 蒺藜cv Jemalong A173中生成了一组突变体的综合集合.,4。快中子, 高能电离诱变, 已被用于在许多植物物种中生成突变体, 包括拟南芥5,6, 大米 (水稻品种)7, 西红柿 (茄汁番茄), 黄豆 (甘氨酸大豆;G. max)8,9, 大麦 (大麦大麦), 和莲花日本人10。从 FNB 诱变衍生出的很大一部分突变是由于 DNA 的缺失, 其范围从几个碱基对到巨型碱基对9,11。许多表型相关基因已被成功识别并具有特征4、12、13、14、15、16、17,18,19. 以前, FNB 突变体的潜在基因的分子克隆依赖于地图的方法, 这是时间消耗和限制分子水平的突变体数量。最近, 一些免费的方法, 包括 transcript-based 方法, 基因组平铺阵列的比较基因组杂交 (计算全息) 的 DNA 拷贝数变异检测, 和整个基因组测序, 已被用来促进不同生物体 (包括动植物) 中缺失突变体的特征20,21,22,2324,25 26,27,28,29,30,31。
为了便于在m. 蒺藜中对 FNB 突变体的定性, 开发并验证了基于基因组的整体比较基因组杂交 (计算全息) 平台。正如在动物系统中报告的那样, 基于阵列的全息计算平台允许在m. 蒺藜FNB 突变体的整个基因组水平检测拷贝数变体 (cnv)。此外, 病变可以通过 PCR 确认和删除边界可以确定的排序。总的来说, 阵列全息计算平台是一个有效的工具, 以识别病变的m 蒺藜FNB 突变体。本文对m 蒺藜FNB 突变体的阵列全息程序和删除边界的 PCR 特征进行了说明。
以下协议提供了实验步骤和有关试剂、设备和分析工具的信息, 这些研究人员有兴趣执行整个基因组阵列的比较基因组杂交 (计算全息) 拷贝数分析植物的变异。例如,苜蓿蒺藜FN6191 突变体用于识别与突变表型相关的缺失区域和候选基因。m 蒺藜FN6191 突变体, 最初是从快中子轰击引发的删除突变的集合中分离出来的32 (参见材料表), 在接种后用土壤展示了一个超级结瘤表型细菌, Sihorhizobium 根瘤菌Sm1021, 与野生型植物形成对比。
Protocol
Representative Results
Discussion
我们已经开发了一个基于阵列的计算全息平台, 用于检测和表征快中子轰击 (FNB) 诱发突变体的m 蒺藜cv Jemalong A17。为了证明阵列全息计算方法在检测基因突变中的应用, 我们对突变 FN6191 进行了 aCGH 分析, 并与野生型植物形成了高结瘤表型, 并与S. 根瘤菌 Sm1021进行了接种。对于分段分析, 如果段中的探测器的日志2比率的平均值高于上限阈值或低于该给定数组比较的下限阈值, 则?…
Divulgations
The authors have nothing to disclose.
Acknowledgements
这项工作的经费部分是由 NSF 植物基因组研究 (IOS-1127155) 的赠款提供的。
Materials
| Medicago truncatula genome array, 1 x 1 M | Agilent | G4123A | |
| Medicago truncatula FN6191 (mutant) | In house | FN6191 | |
| Medicago truncatula Jemalong A17 (reference) | In house | A17 | |
| Sulfuric acid | Sigma-Aldrich | 320501 | |
| DNeasy Plant Mini Kit | Qiagen | 69104 | |
| Nanodrop Spectrophotometer | Thermo Scientific | 1000D | |
| SureTag DNA Labeling Kit | Agilent | 5190-3400 | |
| Random primer | Agilent | 5190-3399 | |
| Acetonitrile | Sigma-Aldrich | 271004-1L | |
| Thermocycler | MJ research | PTC-200 | |
| Centrifuge | Labnet international Inc | Spectrafuge 24D | |
| Stabilization and Drying Solution | Agilent | 5185-5979 | |
| Oligo aCGH/ChIP-on-chip Hybridization Kit | Agilent | 5188-5380 | |
| Hybridization Chamber gasket slides | Agilent | G2505 | |
| Human Cot-1 DNA | Agilent | 5190-3393 | |
| Oligo aCGH/ChIP-on-chip Wash Buffer 1 and 2 | Agilent | 5188-5221 | |
| Hybridization Chamber, stainless | Agilent | G2534A | |
| Hybridization oven | Agilent | G2545A | |
| Purification Columns | Agilent | 5190-3391 | |
| Laser scanner | Roche | MS200 | |
| NimbleScan 2.6 | Roche Nimblegen | 5225035001 | |
| Signal Map 1.9 | Roche Nimblegen | Signalmap1.9 |
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