Skip Navigation



MBE Advance Access published online on February 23, 2005
Molecular Biology and Evolution, doi:10.1093/molbev/msi117
This Article
Right arrow Advance Access manuscript (PDF) Freely available
Right arrow Supplementary Material
Right arrow All Versions of this Article:
22/5/1290    most recent
msi117v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Opazo, J. C.
Right arrow Articles by Lessa, E. P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Opazo, J. C.
Right arrow Articles by Lessa, E. P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2005. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oupjournals.org
Accepted February 21, 2004

Research Article

Adaptive Evolution of the Insulin Gene in Caviomorph Rodents

Juan C. Opazo 1*, R. Eduardo Palma 1, Francisco Melo 2, and Enrique P. Lessa 3

1 Center for Advanced Studies in Ecology & Biodiversity, Departamento de Ecología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
2 Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 6513677, Chile
3 Laboratorio de Evolución, Facultad de Ciencias, Universidad de la República, Casilla 12106, Montevideo 11300, Uruguay

* To whom correspondence should be addressed.
Juan C. Opazo, E-mail: jopazo{at}genetics.wayne.edu


  Abstract

Insulin is a conservative molecule among mammals, maintaining both its structure and function. Rodents that belong to the Suborder Hystricognathi represent an exception, having a very divergent molecule with unusual physiological properties. In this work we analyzed the evolutionary pattern of the insulin gene in caviomorph rodents (South American hystricomorph rodents). We found that these rodents have higher rates of no-synonymous: synonymous substitutions (dN/dS) than non-hystricomorph rodents, and that values are heterogeneous inside the group. We estimated codons under positive selection, specifically: the second binding site (A13 and B17) and others related with hexamerization (B18, B20 and B22). In the monomer structure all selected sites formed a single patch around the second binding site. In the hexamer structure, these amino acids were grouped into three major patches. In this structure contacts between B chains involved all selected sites (except B18), and between faces in the center of the molecule all contacts were among selected sites. While there is no clear hypothesis regarding the cause of this drastic change, experimental evidence does show that this group of rodents has some peculiarities in growth function, and, whether coincidental or not, these changes appeared together with important changes in life-history traits.

Keywords: insulin; caviomorph; adaptive evolution; life-history traits; hystricognathi.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 Mol Biol EvolHome page
S.-H. Kim and S. V. Yi
Mammalian Nonsynonymous Sites Are Not Overdispersed: Comparative Genomic Analysis of Index of Dispersion of Mammalian Proteins
Mol. Biol. Evol., April 1, 2008; 25(4): 634 - 642.
[Abstract] [Full Text] [PDF]


Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.