A comparative evolutionary study of transcription networks

TL;DR

This study compares the topological and evolutionary features of transcription networks in bacteria and yeast, revealing differences in feedback, hierarchy, and complexity influenced by gene duplication and organism-specific constraints.

Contribution

It provides a comparative analysis of transcription network evolution across species, highlighting distinct trends in hierarchy and feedback mechanisms.

Findings

Gene duplication significantly influences network structure.

Bacteria show constraints leading to simpler hierarchical networks.

Yeast maintains complex feedback and hierarchical structures.

Abstract

We present a comparative analysis of large-scale topological and evolutionary properties of transcription networks in three species, the two distant bacteria E. coli and B. subtilis, and the yeast S. cerevisiae. The study focuses on the global aspects of feedback and hierarchy in transcriptional regulatory pathways. While confirming that gene duplication has a significant impact on the shaping of all the analyzed transcription networks, our results point to distinct trends between the bacteria, where time constraints in the transcription of downstream genes might be important in shaping the hierarchical structure of the network, and yeast, which seems able to sustain a higher wiring complexity, that includes the more feedback, intricate hierarchy, and the combinatorial use of heterodimers made of duplicate transcription factors.