Salmo salar and Esox lucius full-length cDNA sequences reveal changes in evolutionary pressures on a post-tetraploidization genome

BMC Genomics

Research Article

Stuart G Jantzen¹  Kristian R von Schalburg¹  Ben F Koop¹  Amber M Messmer¹  Jong S Leong¹  Glenn A Cooper¹  Steven JM Jones²  Robert A Holt²  Richard Moore²  Nancy Y Liao²  Sarah Munro²  William S Davidson³ 

[1] Biology, Centre for Biomedical Research, University of Victoria, V8W 3N5, Victoria, British Columbia, Canada;Genome Sciences Centre, BC Cancer Agency, V5Z 4E6, Vancouver, British Columbia, Canada;Molecular Biology and Biochemistry, Simon Fraser University, V5A 1S6, Burnaby, British Columbia, Canada;

关键词: Genome Duplication;    Head Kidney;    Whole Genome Duplication;    Northern Pike;    polyA Tail;   

DOI  :  10.1186/1471-2164-11-279

 received in 2009-12-22, accepted in 2010-04-30,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundSalmonids are one of the most intensely studied fish, in part due to their economic and environmental importance, and in part due to a recent whole genome duplication in the common ancestor of salmonids. This duplication greatly impacts species diversification, functional specialization, and adaptation. Extensive new genomic resources have recently become available for Atlantic salmon (Salmo salar), but documentation of allelic versus duplicate reference genes remains a major uncertainty in the complete characterization of its genome and its evolution.ResultsFrom existing expressed sequence tag (EST) resources and three new full-length cDNA libraries, 9,057 reference quality full-length gene insert clones were identified for Atlantic salmon. A further 1,365 reference full-length clones were annotated from 29,221 northern pike (Esox lucius) ESTs. Pairwise dN/dS comparisons within each of 408 sets of duplicated salmon genes using northern pike as a diploid out-group show asymmetric relaxation of selection on salmon duplicates.Conclusions9,057 full-length reference genes were characterized in S. salar and can be used to identify alleles and gene family members. Comparisons of duplicated genes show that while purifying selection is the predominant force acting on both duplicates, consistent with retention of functionality in both copies, some relaxation of pressure on gene duplicates can be identified. In addition, there is evidence that evolution has acted asymmetrically on paralogs, allowing one of the pair to diverge at a faster rate.

【 授权许可】

Unknown   
© Leong et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.