Table of Contents
ISRN Microbiology
Volume 2011, Article ID 469053, 6 pages
Research Article

Glucan Biosynthesis Protein G Is a Suitable Reference Gene in Escherichia coli K-12

1Raffles Institution, One Raffles Institution Lane, Singapore 575954
2Department of Zoology, The University of Melbourne, Genetics Lane, Parkville, Victoria 3010, Australia

Received 29 August 2011; Accepted 13 October 2011

Academic Editors: H. I. Atabay and H.-P. Horz

Copyright © 2011 Sean S. J. Heng et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The expressions of reference genes used in gene expression studies are assumed to be stable under most circumstances. However, a number of studies had demonstrated that such genes were found to vary under experimental conditions. In addition, genes that are stably expressed in an organ may not be stably expressed in other organs or other organisms, suggesting the need to identify reference genes for each organ and organism. This study aims at identifying stably expressed genes in Escherichia coli. Microarray datasets from E. coli substrain MG1655 and 1 dataset from W3110 were analysed. Coefficient of variance (COV) of was calculated and 10% of the lowest COV from 4631 genes common in the 3 MG1655 sets were analysed using NormFinder. Glucan biosynthesis protein G (mdoG), which is involved in cell wall synthesis, displayed the lowest weighted COV and weighted NormFinder Stability Index for the MG1655 datasets, while also showing to be the most stable in the dataset for substrain W3110, suggesting that mdoG is a suitable reference gene for E. coli K-12. Gene ontology over-representation analysis on the 39 genes suggested an over-representation of cell division, carbohydrate metabolism, and protein synthesis which supports the short generation time of E. coli.