title: Origin and timing of the horizontal transfer of a PgiC gene from Poa to Festuca ovina.
abstract: A segregating second locus, PgiC2, for the enzyme phosphoglucose isomerase (PGIC) is found in the grass sheep's fescue, Festuca ovina. We have earlier reported that a phylogenetic analysis indicates that PgiC2 has been horizontally transferred from the reproductively separated grass genus Poa. Here we extend our analysis to include intron and exon information on 27 PgiC sequences from 18 species representing five genera, and confirm our earlier finding. The origin of PgiC2 can be traced to a group of closely interrelated, polyploid and partially asexual Poa species. The sequence most similar to PgiC2 is found in Poa palustris with a divergence, based on synonymous substitutions, of only 0.67%. This value suggests that the transfer took place less than 600,000 years ago (late Pleistocene), at a time when most extant Poa and Festuca species already existed.
authors.affiliation: Department of Cell and Organism Biology, Lund University, Genetics Building, Sölvegatan 29, SE-223 62 Lund, Sweden. pernilla.vallenback@cob.lu.se
authors.forename: Pernilla
authors.initials: P
authors.lastname: Vallenback
authors.forename: Maarit
authors.initials: M
authors.lastname: Jaarola
authors.forename: Lena
authors.initials: L
authors.lastname: Ghatnekar
authors.forename: Bengt O
authors.initials: BO
authors.lastname: Bengtsson
mesh_terms: D019143:Evolution, Molecular; D031751:Festuca / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D022761:Gene Transfer, Horizontal; D005956:Glucose-6-Phosphate Isomerase / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D031785:Poa / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D013997:Time Factors
chemical_list: D010940:Plant Proteins; D005956:Glucose-6-Phosphate Isomerase