Open AccessA spectrum of modularity in multi‐functional gene circuits
Author(s) -
Jiménez Alba,
Cotterell James,
Munteanu Andreea,
Sharpe James
Publication year - 2017
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.15252/msb.20167347
Subject(s) - modularity (biology) , electronic circuit , modular design , biology , function (biology) , network analysis , computer science , simple (philosophy) , systems biology , electrical element , biological neural network , theoretical computer science , topology (electrical circuits) , computational biology , mathematics , neuroscience , physics , genetics , philosophy , epistemology , quantum mechanics , operating system , combinatorics
A major challenge in systems biology is to understand the relationship between a circuit's structure and its function, but how is this relationship affected if the circuit must perform multiple distinct functions within the same organism? In particular, to what extent do multi‐functional circuits contain modules which reflect the different functions? Here, we computationally survey a range of bi‐functional circuits which show no simple structural modularity: They can switch between two qualitatively distinct functions, while both functions depend on all genes of the circuit. Our analysis reveals two distinct classes: hybrid circuits which overlay two simpler mono‐functional sub‐circuits within their circuitry, and emergent circuits, which do not. In this second class, the bi‐functionality emerges from more complex designs which are not fully decomposable into distinct modules and are consequently less intuitive to predict or understand. These non‐intuitive emergent circuits are just as robust as their hybrid counterparts, and we therefore suggest that the common bias toward studying modular systems may hinder our understanding of real biological circuits.