Identification and characterization of lineage-specific genes in Populus trichocarpa
Lin, Wu-Ling, B. Cai, and Z. Cheng.  2014.  Plant Cell, Tissue, and Organ Culture., 116:217225.

Abstract:
Species- or lineage-specific genes can facilitate studying thie unique characteristics or biological processes. Updated genome sequences in Populus trichocarpa were screened against thirty newly-sequenced or re-sequenced plant genomes to identify a set of species-specific genes (PtSS). Forty PtSS genes have been isolated with no similarity to any sequence outside the P. trichocarpa genome, therefore have no annotated functions. Protein motif, intron/exon features, subcellular localization and gene expression were analyzed in these PtSS genes. Results reflect their basic genic characters, expression analysis and primary function exploration might provide insight to their possible involvements in lineage specific biological process in woody plants.