title: Evolution of glutamate dehydrogenase genes: evidence for lateral gene transfer within and between prokaryotes and eukaryotes.
abstract: BACKGROUND
  Lateral gene transfer can introduce genes with novel functions into genomes or replace genes with functionally similar orthologs or paralogs. Here we present a study of the occurrence of the latter gene replacement phenomenon in the four gene families encoding different classes of glutamate dehydrogenase (GDH), to evaluate and compare the patterns and rates of lateral gene transfer (LGT) in prokaryotes and eukaryotes.
  
  
  RESULTS
  We extend the taxon sampling of gdh genes with nine new eukaryotic sequences and examine the phylogenetic distribution pattern of the various GDH classes in combination with maximum likelihood phylogenetic analyses. The distribution pattern analyses indicate that LGT has played a significant role in the evolution of the four gdh gene families. Indeed, a number of gene transfer events are identified by phylogenetic analyses, including numerous prokaryotic intra-domain transfers, some prokaryotic inter-domain transfers and several inter-domain transfers between prokaryotes and microbial eukaryotes (protists).
  
  
  CONCLUSIONS
  LGT has apparently affected eukaryotes and prokaryotes to a similar extent within the gdh gene families. In the absence of indications that the evolution of the gdh gene families is radically different from other families, these results suggest that gene transfer might be an important evolutionary mechanism in microbial eukaryote genome evolution.
authors.affiliation: The Canadian Institute for Advanced Research, Program in Evolutionary Biology, Department of Biochemistry & Molecular Biology, Dalhousie University, Sir Charles Tupper Medical Building, Halifax, Nova Scotia, B3H 1X5, Canada. Jan.Andersson@icm.uu.se
authors.forename: Jan O
authors.initials: JO
authors.lastname: Andersson
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Roger
mesh_terms: D020418:Algal Proteins / Q000235:genetics; D000818:Animals; D001419:Bacteria / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D000460:Chlorophyta / Q000201:enzymology / Q000235:genetics; D020564:Deltaproteobacteria / Q000201:enzymology / Q000235:genetics; D016828:Diplomonadida / Q000201:enzymology / Q000235:genetics; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal / Q000235:genetics*; D020745:Genome, Archaeal; D016680:Genome, Bacterial; D018503:Genome, Protozoan; D005969:Glutamate Dehydrogenase / Q000235:genetics*; D008969:Molecular Sequence Data; D000461:Rhodophyta / Q000201:enzymology / Q000235:genetics; D016834:Trichomonadida / Q000201:enzymology / Q000235:genetics
chemical_list: D020418:Algal Proteins; D001426:Bacterial Proteins; D005969:Glutamate Dehydrogenase