Gene activity is distributed unevenly in homogenous cell populations

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Gene activity is distributed unevenly in homogenous cell populations

http://www.medicalnewstoday.com/medicalnews.php?newsid=31571

05 Oct 2005

Göteborg, Sweden - Researchers at TATAA Biocenter, Chalmers

University of Technology, Lund University, and Oxford University

reveal in the current issue of Genome Research that only a small

proportion of cells in an apparently homogenous cell population

account for the bulk of the total amount of transcript present.

Expression levels in a cell population follow a highly slanted

distribution, which is distinctly different from the symmetric normal

distribution in gene activity commonly assumed in homogeneous cell

populations.

Using ultra-sensitive methods they managed to accurately quantify

gene activity in individual _-cells from pancreas and in single cells

from a tumor cell line. They also find that expression of some genes

is highly correlated on the cell level, while expression of other

genes may vary substantially.

This implies that even in a seemingly homogeneous cell population the

gene activity in the cells is highly individual.

In fact, variation is so large that a cell population, in most cases,

cannot be considered homogeneous. This finding will have major

implications on most studies of gene expression and interpretations

thereof.

Ref:

Bengtsson M, Ståhlberg A, Rorsman P and Kubista M.

Gene expression profiling in single cells from the pancreatic islets

of Langerhans reveals lognormal distribution of mRNA levels. 2005.

Genome Research 15(10): 1388-1392.

genome.org/cgi/doi/10.1101/gr.3820805.

SOURCE: cshl.edu