title: A genome-wide scan for genes under balancing selection in Drosophila melanogaster.
abstract: In the history of population genetics balancing selection has been considered as an important evolutionary force, yet until today little is known about its abundance and its effect on patterns of genetic diversity. Several well-known examples of balancing selection have been reported from humans, mice, plants, and parasites. However, only very few systematic studies have been carried out to detect genes under balancing selection. We performed a genome scan in Drosophila melanogaster to find signatures of balancing selection in a derived (European) and an ancestral (African) population. We screened a total of 34 genomes searching for regions of high genetic diversity and an excess of SNPs with intermediate frequency.
  
  
  
  In total, we found 183 candidate genes: 141 in the European population and 45 in the African one, with only three genes shared between both populations. Most differences between both populations were observed on the X chromosome, though this might be partly due to false positives. Functionally, we find an overrepresentation of genes involved in neuronal development and circadian rhythm. Furthermore, some of the top genes we identified are involved in innate immunity.
  
  
  
  Our results revealed evidence of genes under balancing selection in European and African populations. More candidate genes have been found in the European population. They are involved in several different functions.
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany. croze@bio.lmu.de.
authors.forename: Myriam
authors.initials: M
authors.lastname: Croze
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Wollstein
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany.
authors.forename: Vedran
authors.initials: V
authors.lastname: Božičević
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany.|Center of Food and Life Sciences Weihenstephan, Technische Universität München, 85354, Freising, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Živković
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany.|Natural History Museum Berlin, 10115, Berlin, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Stephan
authors.affiliation: Section of Evolutionary Biology, Department of Biology II, University of Munich (LMU), Grosshaderner Str. 2, 82152, Planegg-Martinsried, Germany.
authors.forename: Stephan
authors.initials: S
authors.lastname: Hutter
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004331:Drosophila melanogaster / Q000235:genetics*; D019143:Evolution, Molecular; D014644:Genetic Variation; D005828:Genetics, Population; D020641:Polymorphism, Single Nucleotide; D012641:Selection, Genetic; D014960:X Chromosome
keywords: Balancing selection; Drosophila melanogaster; Genome scan; Population genetics