title: The complete swine olfactory subgenome: expansion of the olfactory gene repertoire in the pig genome.
abstract: BACKGROUND
  Insects and animals can recognize surrounding environments by detecting thousands of chemical odorants. Olfaction is a complicated process that begins in the olfactory epithelium with the specific binding of volatile odorant molecules to dedicated olfactory receptors (ORs). OR proteins are encoded by the largest gene superfamily in the mammalian genome.
  
  
  RESULTS
  We report here the whole genome analysis of the olfactory receptor genes of S. scrofa using conserved OR gene specific motifs and known OR protein sequences from diverse species. We identified 1,301 OR related sequences from the S. scrofa genome assembly, Sscrofa10.2, including 1,113 functional OR genes and 188 pseudogenes. OR genes were located in 46 different regions on 16 pig chromosomes. We classified the ORs into 17 families, three Class I and 14 Class II families, and further grouped them into 349 subfamilies. We also identified inter- and intra-chromosomal duplications of OR genes residing on 11 chromosomes. A significant number of pig OR genes (n = 212) showed less than 60% amino acid sequence similarity to known OR genes of other species.
  
  
  CONCLUSIONS
  As the genome assembly Sscrofa10.2 covers 99.9% of the pig genome, our analysis represents an almost complete OR gene repertoire from an individual pig genome. We show that S. scrofa has one of the largest OR repertoires, suggesting an expansion of OR genes in the swine genome. A significant number of unique OR genes in the pig genome may suggest the presence of swine specific olfactory stimulation.
authors.affiliation: Department of Animal Biotechnology, Konkuk University, 263 Achasan-ro, Gwangjin-gu, Seoul 143-701, South Korea.
authors.forename: Dinh Truong
authors.initials: DT
authors.lastname: Nguyen
authors.forename: Kyooyeol
authors.initials: K
authors.lastname: Lee
authors.forename: Hojun
authors.initials: H
authors.lastname: Choi
authors.forename: Min-kyeung
authors.initials: MK
authors.lastname: Choi
authors.forename: Minh Thong
authors.initials: MT
authors.lastname: Le
authors.forename: Ning
authors.initials: N
authors.lastname: Song
authors.forename: Jin-Hoi
authors.initials: JH
authors.lastname: Kim
authors.forename: Han Geuk
authors.initials: HG
authors.lastname: Seo
authors.forename: Jae-Wook
authors.initials: JW
authors.lastname: Oh
authors.forename: Kyungtae
authors.initials: K
authors.lastname: Lee
authors.forename: Tae-Hun
authors.initials: TH
authors.lastname: Kim
authors.forename: Chankyu
authors.initials: C
authors.lastname: Park
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D002875:Chromosomes / Q000235:genetics / Q000378:metabolism; D030541:Databases, Genetic; D004285:Dogs; D020440:Gene Duplication; D016678:Genome; D006801:Humans; D051379:Mice; D005810:Multigene Family; D010802:Phylogeny; D051381:Rats; D018035:Receptors, Odorant / Q000235:genetics*; D034421:Sus scrofa / Q000145:classification / Q000235:genetics*
chemical_list: D018035:Receptors, Odorant