1、2023 年 第 4 卷 第 1 期|Synthetic Biology Journal 2023,4(1):204-224拉曼光谱技术在单细胞表型检测与分选中的应用进展王喜先,孙晴,刁志钿,徐健,马波(中国科学院青岛生物能源与过程研究所 单细胞中心,山东 青岛 266101)摘要:基因组测序、编辑与合成技术日新月异,推动了基因型“设计”和“合成”能力的突飞猛进,同时也使人工细胞的表型检测成为合成生物学发展的瓶颈之一。对于细胞功能的快速测试与评价,单细胞分析技术具有重要意义与前景,但理想的解决方案需要具备活体无损、非标记式、提供全景式表型、能分辨复杂功能、快速高通量且低成本、能与组学分析联动等
2、特征。拉曼光谱技术具备上述所有特征,能够提供单细胞的化学成分组成及分子结构等信息,是一种高效的单细胞表型识别技术。本文首先概述了拉曼组概念和基于拉曼组的细胞功能表型识别,包括代谢产物定性和定量、底物代谢和互作表征、细胞种类和状态鉴定以及环境应激检测等;其次,根据拉曼信号的分类、拉曼信号检测模式和目标细胞分选策略,对现有的拉曼分选平台及其在细胞表型分选中的应用进行分析总结;最后,对单细胞拉曼光谱技术在合成细胞表型检测与分选面临的问题、潜在解决策略进行了探讨和展望。单细胞拉曼光谱技术不仅为细胞工厂的高通量、全景式表型检测与筛选提供了全新的解决方案,还将推动“单细胞精度的表型组-功能基因组”作为一种
3、新的生物大数据类型,服务于“数据科学”驱动下的合成生物技术。关键词:合成生物学;拉曼光谱技术;细胞工厂;单细胞表型识别;高通量分选中图分类号:Q939.97 文献标志码:A Advances with applications of Raman spectroscopy in single-cell phenotype sorting and analysisWANG Xixian,SUN Qing,DIAO Zhidian,XU Jian,MA Bo(Single-cell Center,Qingdao Institute of Bioenergy and Bioprocess Techno
4、logy,Chinese Academy of Sciences,Qingdao 266101,Shandong,China)Abstract:In synthetic biology,methodological innovations in sequencing,editing and synthesis of genes and whole genomes have resulted in unprecedented development in“design and manufacturing of genotypes”.On the other hand,“testing of ce
5、llular phenotypes and functions”has increasingly become one of major bottlenecks.Single-cell technologies have tremendous impacts and potentials in rapid testing of cellular phenotypes and functions.However,收稿日期:2022-08-03 修回日期:2022-09-12基金项目:国家重点研发计划“合成生物学”重点专项(2018YFA090290);天津市合成生物技术创新能力提升行动项目(TS
6、BICIP-PTJS-003-05)引用本文:王喜先,孙晴,刁志钿,徐健,马波.拉曼光谱技术在单细胞表型检测与分选中的应用进展 J.合成生物学,2023,4(1):204-224Citation:WANG Xixian,SUN Qing,DIAO Zhidian,XU Jian,MA Bo.Advances with applications of Raman spectroscopy in single-cell phenotype sorting and analysis J.Synthetic Biology Journal,2023,4(1):204-224DOI:10.12211/2
7、096-8280.2022-043特约评述第 4 卷 such single-cell methods should allow non-invasive live-cell probing,be label-free,provide landscape-like phenotype sorting,distinguish complex functions,operate with high speed,sufficient throughput and low-cost,and finally,be able to integrate with downstream omics analy
8、sis.Raman spectroscopy has all the above features,and can provide information on the chemical composition and molecular structure of single cells,making it an efficient single-cell phenotyping technology.In this review,we first introduce the concept of Ramanome and Ramanome-based phenotyping technol
9、ogies,including detecting and quantifying products,measuring profiles of substrates and metabolites,discriminating cell types or states,and characterizing stress response and modeling environmental changes.We then summarize the development of existing Raman-activated cell sorting(RACS)platforms in p
10、henotyping and sorting of cell factories such as including spontaneous Raman,resonance Raman,and coherent Raman,the modes for acquiring Raman signals including static modes on dry slice and in liquid as well,flow modes by trap-free and trap-and-release manners,and principles for target cells sorting
11、 including Ejection by pulsed laser,dragging by optical tweezer,and sorting by microfluidics operation and droplets.We also highlight the applications of different RACS platforms,including the sorting of carotenoid-producing yeast and cyanobacteria cells,astaxanthin(AXT)-hyperproducing microalgae ce
12、lls,triacylglycerol(TAG)-producing yeast cells,etc.Finally,challenges with single cell Raman spectroscopy(SCRS)in the phenotyping and sorting of synthetic cells and their perspectives are outlined and discussed.We propose that SCRS will bridge phenotypes and genotypes in science and technologies thr
13、ough coupling with downstream high-throughput cell sorting and omics profiling.This bridge will lead to novel and creative solutions to high-throughput,landscape-like testing and screening of synthetic cells.Moreover,it will fulfill the promise of Raman spectroscopy-enabled single-cell“phenome-genom
14、e”as a new type of biological big-data,and accelerate the pace of“data-driven”synthetic biology.Keywords:synthetic biology;Raman spectroscopy;cell factory;single-cell phenotyping;high-throughput sorting自2000年自然(Nature)杂志报道人工合成基因线路研究成果以来,合成生物学研究在全世界范围内引起了广泛关注,被多个国家和国际组织机构评为未来的颠覆性技术1-3。合成生物学的核心使命是在阐明并
15、模拟生物合成基本规律的基础之上,人工设计并构建新的、具有特定生理功能的生物系统,从而建立药物、功能材料或能源替代品等的生物制造途径4。其技术的跨越式发展,取决于“基因型设计”“基因型合成”与“细胞表型测试”这三大共性技术环节(design-build-test)的突破5。近年来,借助于芯片技术和下一代高通量测序平台,基因合成的通量、保真度和成本大幅度改进6-8。基因编辑、组装及转移技术的进一步发展,更使得对生命体的改造从单基因操作进入了对整个基因组设计改造的时代9-14。至此,业界构建突变体甚至人工细胞的能力已经突飞猛进。然而,细胞表型测试速度与通量的发展却缓慢得多,有时候甚至落后几个数量20
16、5合成生物学 第 4 卷级。例如,从基因型突变体库来筛选目标表型组合的细胞通常需要花费大量的人力、经费和时间生产抗疟药前体的微生物细胞工厂的筛选约动用了 150 人.年(human-year)的工作量15-16。因此,细胞表型测试已成为合成生物技术发展的“限速步骤”之一。无论是从天然环境中寻找、识别和鉴定生物元件与模块,还是表征、理解和筛选人工设计的基因回路与网络,关键环节之一均是其活性以及功能在活体细胞内的快速测试与评价。单个细胞是地球上生命的基本单元和进化的基本单位,因此,单细胞分析技术,即在单个细胞精度上的功能识别与表征,能够在最“深”的水平挖掘生命元件、刻画细胞功能与理解生命过程17-21。同时,单细胞分析直接分析每个细胞个体的功能,因此可极大缩短培养周期甚至跳过烦琐且耗时的培养过程,从而克服环境中大部分微生物细胞尚难培养这一挑战,这对于从人体与环境微生物组中挖掘 生 物 元 件、模 块 或 底 盘 细 胞 具 有 重 大 的意义22-23。对于细胞功能表型的快速测试而言,理想的单细胞分析/分选技术需要具备6个特征24-25:活体检测。在很多情况下,元件与模块的功能,只有在活体