Skip to Main Content
Skip Nav Destination
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

Gene expression in organisms is controlled by regulatory proteins termed transcriptionfactors, which recognize and bind to specific nucleotide sequences. Over the years, considerableinformation has accumulated on the regulatory interactions between transcription factorsand their target genes in various model prokaryotes, such as Escherichia coli andBacillus subtilis. This has allowed the representation of this information in the form of adirected graph, which is commonly referred to as the transcriptional regulatory network. Thenetwork representation provides us with an excellent conceptual framework to understandthe structure of the transcriptional regulation, both at local and global levels of organization.Several studies suggest that the transcriptional network inferred from model organisms maybe approximated by a scale-free topology, which in turn implies the presence of a relativelysmall group of highly connected regulators (hubs or global regulators). While the graph theoreticalprinciples have been applied to infer various properties of such networks, there havebeen few studies that have actually investigated the evolution of the transcriptional regulatorynetworks across diverse organisms. Using recently developed computational methods thatexploit various evolutionary principles, we have attempted to reconstruct and compare thesenetworks across a wide-range of prokaryotes. This has provided several insights on the modificationand diversification of network structures of various organisms in course of evolution.Firstly, we observed that target genes show a much higher level of conservation thantheir transcriptional regulators. This in turn suggested that the same set of functions could bedifferently controlled across diverse organisms, contributing significantly to their adaptiveradiations. In particular, at the local level of network structure, organism-specific optimizationof the transcription network has evolved primarily via tinkering of individual regulatoryinteractions rather than whole scale reuse or deletion of network motifs (local structure). Inturn, as phylogenetic diversification proceeds, this process appears to have favored repeatedconvergence to scale-free-like structures, albeit with different regulatory hubs.

Send Email

Recipient(s) will receive an email with a link to 'Gene and Protein Evolution > 66 - 80: General Trends in the Evolution of Prokaryotic Transcriptional Regulatory Networks' and will not need an account to access the content.

Subject: Gene and Protein Evolution > 66 - 80: General Trends in the Evolution of Prokaryotic Transcriptional Regulatory Networks

(Optional message may have a maximum of 1000 characters.)

Close Modal

or Create an Account

Close Modal
Close Modal