Phylogenetic analysis of the vertebrate Excitatory/Neutral Amino Acid Transporter (SLC1/EAAT) family reveals lineage specific subfamilies

BMC Evolutionary Biology

Research Article

Stephan CF Neuhauss¹  Matthias Gesemann¹  Colette M Maurer¹  Annegret Lesslauer²  Helia B Schönthaler³ 

[1] Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland;Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland;Department of Biology, Swiss Federal Institute of Technology (ETH) Zurich, Switzerland;Institute of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland;Fondation BBVA-Cancer Cell Biology Programme, Spanish National Cancer Reseach Center (CNIO), E-28029, Madrid, Spain;

关键词: Genome Duplication;    Zebrafish Genome;    Excitatory Amino Acid Transporter;    SLC1 Gene;    Elephant Shark;   

DOI  :  10.1186/1471-2148-10-117

 received in 2010-01-13, accepted in 2010-04-29,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundThe composition and expression of vertebrate gene families is shaped by species specific gene loss in combination with a number of gene and genome duplication events (R1, R2 in all vertebrates, R3 in teleosts) and depends on the ecological and evolutionary context. In this study we analyzed the evolutionary history of the solute carrier 1 (SLC1) gene family. These genes are supposed to be under strong selective pressure (purifying selection) due to their important role in the timely removal of glutamate at the synapse.ResultsIn a genomic survey where we manually annotated and analyzing sequences from more than 300 SLC1 genes (from more than 40 vertebrate species), we found evidence for an interesting evolutionary history of this gene family. While human and mouse genomes contain 7 SLC1 genes, in prototheria, sauropsida, and amphibia genomes up to 9 and in actinopterygii up to 13 SLC1 genes are present. While some of the additional slc1 genes in ray-finned fishes originated from R3, the increased number of SLC1 genes in prototheria, sauropsida, and amphibia genomes originates from specific genes retained in these lineages.Phylogenetic comparison and microsynteny analyses of the SLC1 genes indicate, that theria genomes evidently lost several SLC1 genes still present in the other lineage. The genes lost in theria group into two new subfamilies of the slc1 gene family which we named slc1a8/eaat6 and slc1a9/eaat7.ConclusionsThe phylogeny of the SLC1/EAAT gene family demonstrates how multiple genome reorganization and duplication events can influence the number of active genes. Inactivation and preservation of specific SLC1 genes led to the complete loss of two subfamilies in extant theria, while other vertebrates have retained at least one member of two newly identified SLC1 subfamilies.

【 授权许可】

CC BY   
© Gesemann et al; licensee BioMed Central Ltd. 2010