title: Enrichment of Triticum aestivum gene annotations using ortholog cliques and gene ontologies in other plants.
abstract: BACKGROUND
  While the gargantuan multi-nation effort of sequencing T. aestivum gets close to completion, the annotation process for the vast number of wheat genes and proteins is in its infancy. Previous experimental studies carried out on model plant organisms such as A. thaliana and O. sativa provide a plethora of gene annotations that can be used as potential starting points for wheat gene annotations, proven that solid cross-species gene-to-gene and protein-to-protein correspondences are provided.
  
  
  RESULTS
  DNA and protein sequences and corresponding annotations for T. aestivum and 9 other plant species were collected from Ensembl Plants release 22 and curated. Cliques of predicted 1-to-1 orthologs were identified and an annotation enrichment model was defined based on existing gene-GO term associations and phylogenetic relationships among wheat and 9 other plant species. A total of 13 cliques of size 10 were identified, which represent putative functionally equivalent genes and proteins in the 10 plant species. Eighty-five new and more specific GO terms were associated with wheat genes in the 13 cliques of size 10, which represent a 65% increase compared with the previously 130 known GO terms. Similar expression patterns for 4 genes from Arabidopsis, barley, maize and rice in cliques of size 10 provide experimental evidence to support our model. Overall, based on clique size equal or larger than 3, our model enriched the existing gene-GO term associations for 7,838 (8%) wheat genes, of which 2,139 had no previous annotation.
  
  
  CONCLUSIONS
  Our novel comparative genomics approach enriches existing T. aestivum gene annotations based on cliques of predicted 1-to-1 orthologs, phylogenetic relationships and existing gene ontologies from 9 other plant species.
authors.affiliation: Information and Communications Technologies, National Research Council Canada, Moncton, New Brunswick, E1A 7R1, Canada. dan.tulpan@nrc-cnrc.gc.ca.
authors.forename: Dan
authors.initials: D
authors.lastname: Tulpan
authors.affiliation: Information and Communications Technologies, National Research Council Canada, Moncton, New Brunswick, E1A 7R1, Canada. serge.leger@nrc-cnrc.gc.ca.
authors.forename: Serge
authors.initials: S
authors.lastname: Leger
authors.affiliation: Information and Communications Technologies, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada. alain.tchagang@nrc-cnrc.gc.ca.
authors.forename: Alain
authors.initials: A
authors.lastname: Tchagang
authors.affiliation: Information and Communications Technologies, National Research Council Canada, Ottawa, Ontario, K1A 0R6, Canada. youlian.pan@nrc-cnrc.gc.ca.
authors.forename: Youlian
authors.initials: Y
authors.lastname: Pan
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D005075:Biological Evolution; D018744:DNA, Plant / Q000737:chemistry / Q000378:metabolism; D017343:Genes, Plant; D001467:Hordeum / Q000235:genetics; D008957:Models, Genetic; D058977:Molecular Sequence Annotation; D012275:Oryza / Q000235:genetics; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000378:metabolism; D014908:Triticum / Q000145:classification / Q000235:genetics*; D003313:Zea mays / Q000235:genetics
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins