Conserved ortholog sets in forest trees
Putative single-copy genes and conserved ortholog sets (COS) were identified in model plant species thale cress (Arabidopsis thaliana), rice (Oryza sativa ssp. japonica), and poplar [black cottonwood, Populus trichocarpa (Torr. & Gray ex Brayshaw)] and used to find putative COS in four conifers (the Coniferales order). Using expressed sequence tag sequences, unique transcript sets were assembled in loblolly pine (Pinus taeda L.), white spruce [Picea glauca (Moench) Voss], Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco var. menziesii], and sugi [Cryptomeria japonica (Thunberg ex Linnaeus f.) D. Don]. They were compared with COS sets identified in three model plant species using comparative sequence analysis. Almost half of the single-copy genes in herbaceous species (Arabidopsis and rice) had additional copies and homologs in poplar and conifers. The identified tentative COS sets have many applications in evolutionary genomics studies, phylogenetic analysis, and comparative mapping.
KeywordsCOS Cryptomeria japonica EST Ortholog Picea glauca Pinus taeda Populus trichocarpa Pseudotsuga menziesii Unique transcript
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