Gene expression profiling in single cells from the pancreatic islets of Langerhans reveals lognormal distribution of mRNA levels
- 1 Department of Experimental Medical Science, Lund University, 221 84 Lund, Sweden
- 2 Department of Chemistry and Biosciences, Molecular Biotechnology, Chalmers University of Technology and TATAA Biocenter, Lundberg Laboratory, 405 30 Göteborg, Sweden
- 3 The Oxford Centre for Diabetes, Endocrinology and Metabolism, The Churchill Hospital, Oxford, OX3 7LJ, United Kingdom
Abstract
The transcriptional machinery in individual cells is controlled by a relatively small number of molecules, which may result in stochastic behavior in gene activity. Because of technical limitations in current collection and recording methods, most gene expression measurements are carried out on populations of cells and therefore reflect average mRNA levels. The variability of the transcript levels between different cells remains undefined, although it may have profound effects on cellular activities. Here we have measured gene expression levels of the five genes ActB, Ins1, Ins2, Abcc8, and Kcnj11 in individual cells from mouse pancreatic islets. Whereas Ins1 and Ins2 expression show a strong cell–cell correlation, this is not the case for the other genes. We further found that the transcript levels of the different genes are lognormally distributed. Hence, the geometric mean of expression levels provides a better estimate of gene activity of the typical cell than does the arithmetic mean measured on a cell population.
Footnotes
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[Supplemental material is available online at www.genome.org.]
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Article and publication are at http://www.genome.org/cgi/doi/10.1101/gr.3820805.
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↵4 Corresponding author. E-mail martin.bengtsson{at}med.lu.se; fax +46-46-2227763.
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- Accepted June 28, 2005.
- Received February 11, 2005.
- Cold Spring Harbor Laboratory Press
