Cell population heterogeneity in expression of a gene-switching network with fluorescent markers of different half-lives.
Cell population heterogeneity in expression of a gene-switching network with fluorescent markers of different half-lives.
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具有不同半衰期的荧光标记的基因开关网络表达的细胞群异质性。
DOI：
10.1016/j.jbiotec.2006.09.026
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发表时间：
2007
影响因子：
4.1
通讯作者：
Mantzaris,Nikos
中科院分区：
文献类型：
--
作者：
Portle,Stephanie;Causey,ThomasB;Wolf,Kim;Bennett,GeorgeN;San,Ka-Yiu;Mantzaris,Nikos
我们研究了表达水平的分布之间的细胞的大肠杆菌人口携带基因开关网络，称为遗传切换。采用两种不同半衰期的绿色荧光蛋白（GFP）报告蛋白，研究了异丙基-β-d-硫代半乳糖苷（IPTG）诱导剂浓度对GFP报告蛋白荧光分布特性的影响。我们的流式细胞术测量表明，由于所研究的细胞群体的高度异质性，荧光表型的扩散为一到三个数量级。此外，在一个特定的准时不变的参考状态，定义用于比较的目的，分布的形状强烈依赖于诱导剂的浓度。对于非常低和非常高的诱导剂浓度，在参考状态下的分布是单峰的。相反，对于中间IPTG浓度，在低于和高于单细胞阈值的情况下形成两个不同的亚群，导致具有双峰形状的分布。观察到双峰的诱导剂浓度区域是相同的，并且与GFP半衰期无关。双峰数密度函数不仅在参考状态下获得。瞬时研究表明，即使在参考状态下的分布是单峰的情况下，在群体通过单细胞诱导阈值所需的一段时间内，分布也会变成双峰。然而，该特征仅被具有减少的半衰期GFP的系统捕获。一个简单的单细胞模型用于阐明诱导剂浓度和GFP半衰期对实验测量的数密度函数的形状的影响。广泛的荧光表型和平均群体特性无法完全表征网络行为，表明在设计用于生物技术和生物医学应用的基因开关网络时考虑细胞群体异质性的重要性。
We studied the distribution of expression levels amongst the cells of an Escherichia coli population carrying a gene-switching network, known as the genetic toggle. We employed two green fluorescent protein (GFP) reporter proteins with different half-lives and characterized the effect of isopropyl-β-d-thiogalactopyranoside (IPTG) inducer concentration on fluorescence distribution characteristics. Our flow cytometric measurements indicated that there is a spread of fluorescence phenotypes of one to three orders of magnitude, due to the highly heterogeneous nature of the cell populations under investigation. Moreover, the shape of the distribution at a specific quasi-time-invariant reference state, defined for comparison purposes, strongly depended on inducer concentration. For very low and very high inducer concentrations, the distributions at the reference state are unimodal. On the contrary, for intermediate IPTG concentrations, two distinct subpopulations were formed below and above a single-cell threshold, resulting in distributions with a bimodal shape. The region of inducer concentrations where bimodality is observed is the same and independent of GFP half-life. Bimodal number density functions are not only obtained at the reference state. Transient studies revealed that even in cases where the distribution at the reference state is unimodal, the distribution becomes bimodal for a period of time required for the population to pass through the single-cell induction threshold. However, this feature was only captured by the system with the reduced half-life GFP. A simple single-cell model was used to shed light into the effect of inducer concentration and GFP half-life on the shape of the experimentally measured number density functions. The wide range of fluorescent phenotypes and the inability of the average population properties to fully characterize network behavior, indicate the importance of taking into account cell population heterogeneity when designing such a gene-switching network for biotechnological and biomedical applications.
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影响因子：
3.5
作者：
Cormack, BP;Valdivia, RH;Falkow, S
通讯作者：
Falkow, S
DOI：
10.1016/0025-5564(67)90008-9
发表时间：
1967-01-01
期刊：
MATH BIO SCL
影响因子：
--
作者：
FREDERICKSON, A. G.;RAMKRISHNA, D.;TSUCHIYA, H. M.
通讯作者：
TSUCHIYA, H. M.
异质细胞群动态的随机和确定性模拟。
影响因子：
2
作者：
Mantzaris,NikosV
通讯作者：
Mantzaris,NikosV
细菌病毒（噬菌体）生长中的爆发大小分布
影响因子：
3.2
作者：
M. Delbrück
通讯作者：
M. Delbrück
有丝分裂时 Numb 的不等分配调节二元细胞死亡决策。
影响因子：
4.6
作者：
V. Orgogozo;F. Schweisguth;Y. Bellaïche
通讯作者：
Y. Bellaïche