News 2009 - A rapid and efficient...
A rapid and efficient cell sorting method allows new insights into early animal embryogenesis
Close Collaboration between Max Delbrück Center and New York University
Ten thousand embryos -- and counting
Ten thousand C. elegans embryos -- collected at single-cell stage!
A technique to collect large numbers of worm embryos, all precisely the same age, has been developed in a collaborative approach of researchers at the MDC and NYU. This major new technique and subsequent transcriptional analysis are reported online this week in Nature Methods. The field is now open for detailed studies of early events during embryogenesis.
The researchers are members of and partially funded by the newly launched PhD exchange program of the BIMSB, allowing groups in Berlin and New York to conduct joint projects. The students are being trained in both locations, travelling back and forth, as required for the projects and the PhD education.
The worm Caenorhabditis elegans is a popular animal model for biologists and extensive developmental studies. Yet, to date, it has not been possible to collect large numbers of embryos at the same developmental stage, a prerequisite to studying gene expression and protein interactions on a genome-wide scale. The current method of choice is collecting the embryos by hand, which is time consuming and does not yield adequate sample size for large-scale studies.
Nikolaus Rajewsky and colleagues improve the process using fluorescence-activated cell sorting (FACS). They create embryos that express a stage-specific protein fused to a fluorescent marker; when the embryo reaches the particular stage, it fluoresces. This is an ideal way to rapidly collect tens of thousands of embryos at the same stage.
Making use of this technique, the scientists carried out high-throughput sequencing to profile small RNA populations in embryos, and gained insight into how gene expression changes during the first cell cycles in a worm embryo.
Reference:
Stoeckius M; Maaskola J; Colombo T; Rahn HP; Friedlaender MR; Li N; Chen W; Piano F; Rajewsky N
Large-scale sorting of C. elegans embryos reveals the dynamics of small RNA expression
Nature Methods 6 (10): 745-751 (2009-10)
Links:
Author contact:
Nikolaus Rajewsky (Max Delbrück Center for Molecular Medicine, Berlin, Germany)
phone: +49 30 9406 2999
E-mail: rajewsky@mdc-berlin.de