大脑细胞的异质性对于科学家了解不同神经细胞群体的生物特性是一个很大的障碍，在11月14日出版的《细胞》（Cell）上，美国的Myriam Heiman等科学家提出了一种全新的细胞特异性标记技术，而在本期刊物的另一篇文章中，Doyle等科学家利用这一标记方法实现了对脑部特定细胞群落的分子区分。
Heiman等科学家利用在细胞群落中表达EGFP标记核糖体蛋白L10a的细菌人工染色体转基因小鼠，发明了一种对大脑中特定细胞群落的多核糖体mRNA进行亲和纯化的方法。通过对4种不同种类的神经元的比较分析，研究小组发现了数以百计的区分以上4种细胞群落的基因。文章作者表示，即使是两种在形态上无法区分的相互混杂的中型多棘神经元，也在其翻译模式中存在极大的差异。科学家将这种基因标记方法称为翻译核糖体亲和纯化（translating ribosome affinity purification TRAP）法，它是一种能发现由于基因改变、疾病或者药理学原因导致的细胞分子变化的方法。
在另一篇文章中，美国洛克菲勒大学的Doyle等人证实了上述方法的一般性。比较分析能为科学家更深入地研究复杂生物体系提供帮助。研究人员建立了特定细胞群落的翻译模式，文章中作者表示，数以千计的细胞特异性mRNA并不会在整个组织的微阵列分析过程中被去除。科学家提出了16个转基因小鼠世系的相应中枢神经系统结构的解剖学特征以及翻译模式，这些信息对于研究神经细胞将非常有帮助。 （生物谷Bioon.com）
生物谷推荐原始出处：
Cell，Volume 135, Issue 4, 738-748，Myriam Heiman，Nathaniel Heintz
A Translational Profiling Approach for the Molecular Characterization of CNS Cell Types
Myriam Heiman1,Anne Schaefer1,Shiaoching Gong2,Jayms D. Peterson5,Michelle Day5,Keri E. Ramsey6,Mayte Suárez-Fari?as4,Cordelia Schwarz3,Dietrich A. Stephan6,D. James Surmeier5,Paul Greengard1andNathaniel Heintz2,3,,
1 Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
2 GENSAT Project, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
3 Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
4 The Rockefeller University Hospital, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
5 Department of Physiology, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA
6 Neurogenomics Division, Translational Genomics Research Institute, 445 North 5th Street, Phoenix, AZ 85004, USA
SUMMARY
The cellular heterogeneity of the brain confounds efforts to elucidate the biological properties of distinct neuronal populations. Using bacterial artificial chromosome (BAC) transgenic mice that express EGFP-tagged ribosomal protein L10a in defined cell populations, we have developed a methodology for affinity purification of polysomal mRNAs from genetically defined cell populations in the brain. The utility of this approach is illustrated by the comparative analysis of four types of neurons, revealing hundreds of genes that distinguish these four cell populations. We find that even two morphologically indistinguishable, intermixed subclasses of medium spiny neurons display vastly different translational profiles and present examples of the physiological significance of such differences. This genetically targeted translating ribosome affinity purification (TRAP) methodology is a generalizable method useful for the identification of molecular changes in any genetically defined cell type in response to genetic alterations, disease, or pharmacological perturbations.
Cell，Volume 135, Issue 4, 749-762，Joseph P. Doyle，Nathaniel Heintz
Application of a Translational Profiling Approach for the Comparative Analysis of CNS Cell Types
Joseph P. Doyle1,4,Joseph D. Dougherty1,4,Myriam Heiman2,Eric F. Schmidt1,Tanya R. Stevens1,Guojun Ma1,Sujata Bupp1,Prerana Shrestha1,Rajiv D. Shah1,Martin L. Doughty3,Shiaoching Gong1,3,Paul Greengard2andNathaniel Heintz1,3,,
1 Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
2 Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
3 GENSAT Project, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
4 These authors contributed equally to this work
SUMMARY
Comparative analysis can provide important insights into complex biological systems. As demonstrated in the accompanying paper, translating ribosome affinity purification (TRAP) permits comprehensive studies of translated mRNAs in genetically defined cell populations after physiological perturbations. To establish the generality of this approach, we present translational profiles for 24 CNS cell populations and identify known cell-specific and enriched transcripts for each population. We report thousands ofcell-specific mRNAs that were not detected in whole-tissue microarray studies and provide examples that demonstrate the benefits deriving from comparative analysis. To provide a foundation for further biological and insilico studies, we provide a resource of 16 transgenic mouse lines, their corresponding anatomic characterization, and translational profiles for cell types from a variety of central nervous system structures. This resource will enable a wide spectrum of molecular and mechanistic studies of both well-known and previously uncharacterized neural cell populations.
