Research article

Does negative auto-regulation increase gene duplicability?

Tobias Warnecke¹ , Guang-Zhong Wang² , Martin J Lercher² and Laurence D Hurst¹

¹Department of Biology & Biochemistry, University of Bath, UK

²Bioinformatics Group, Heinrich-Heine-University Düsseldorf, Germany

author email corresponding author email

BMC Evolutionary Biology 2009, 9:193doi:10.1186/1471-2148-9-193

Published:	7 August 2009

Abstract

Background

A prerequisite for a duplication to spread through and persist in a given population is retaining expression of both gene copies. Yet changing a gene's dosage is frequently detrimental to fitness. Consequently, dosage-sensitive genes are less likely to duplicate.

However, in cases where the level of gene product is controlled, via negative feedback, by its own abundance, an increase in gene copy number can in principle be decoupled from an increase in protein while both copies remain expressed. Using data from the transcriptional networks of E. coli and S. cerevisiae, we test the hypothesis that genes under negative auto-regulation show enhanced duplicability.

Results

Controlling for several known correlates of duplicability, we find no statistically significant support in either E. coli or S. cerevisiae that transcription factors under negative auto-regulation hold a duplicability advantage over transcription factors with no auto-regulation.

Conclusion

Based on the analysis of transcriptional networks in E. coli and S. cerevisiae, there is no evidence that negative auto-regulation has contributed, on a genome-wide scale, to the variability in gene family sizes in these species.