RT Journal
A1 Bengtsson, Martin
A1 Ståhlberg, Anders
A1 Rorsman, Patrik
A1 Kubista, Mikael
T1 Gene expression profiling in single cells from the pancreatic islets of Langerhans reveals lognormal distribution of mRNA levels
JF Genome Research 
JO Genome Research 
YR 2005 
FD October 01 
VO 15 
IS 10 
SP 1388 
OP 1392 
DO 10.1101/gr.3820805 
UL http://genome.cshlp.org/content/15/10/1388.abstract 
AB 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.