title: High variability and non-neutral evolution of the mammalian avpr1a gene.
abstract: BACKGROUND
  The arginine-vasopressin 1a receptor has been identified as a key determinant for social behaviour in Microtus voles, humans and other mammals. Nevertheless, the genetic bases of complex phenotypic traits like differences in social and mating behaviour among species and individuals remain largely unknown. Contrary to previous studies focusing on differences in the promotor region of the gene, we investigate here the level of functional variation in the coding region (exon 1) of this locus.
  
  
  RESULTS
  We detected high sequence diversity between higher mammalian taxa as well as between species of the genus Microtus. This includes length variation and radical amino acid changes, as well as the presence of distinct protein variants within individuals. Additionally, negative selection prevails on most parts of the first exon of the arginine-vasopressin receptor 1a (avpr1a) gene but it contains regions with higher rates of change that harbour positively selected sites. Synonymous and non-synonymous substitution rates in the avpr1a gene are not exceptional compared to other genes, but they exceed those found in related hormone receptors with similar functions.
  
  
  CONCLUSIONS
  These results stress the importance of considering variation in the coding sequence of avpr1a in regards to associations with life history traits (e.g. social behaviour, mating system, habitat requirements) of voles, other mammals and humans in particular.
authors: Computational and Molecular Population Genetics (CMPG), Zoological Institute, University of Bern, Baltzerstrasse 6, CH-3012 Bern, Switzerland. sabine.fink@zoo.unibe.ch
authors: Sabine
authors: S
authors: Fink
authors: Laurent
authors: L
authors: Excoffier
authors: Gerald
authors: G
authors: Heckel
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D003411:Arvicolinae / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation; D016133:Polymerase Chain Reaction; D017483:Receptors, Vasopressin / Q000235:genetics*; D012641:Selection, Genetic; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D017483:Receptors, Vasopressin