title: Conserved expression of natural antisense transcripts in mammals.
abstract: BACKGROUND
  Recent studies had found thousands of natural antisense transcripts originating from the same genomic loci of protein coding genes but from the opposite strand. It is unclear whether the majority of antisense transcripts are functional or merely transcriptional noise.
  
  
  RESULTS
  Using the Affymetrix Exon array with a modified cDNA synthesis protocol that enables genome-wide detection of antisense transcription, we conducted large-scale expression analysis of antisense transcripts in nine corresponding tissues from human, mouse and rat. We detected thousands of antisense transcripts, some of which show tissue-specific expression that could be subjected to further study for their potential function in the corresponding tissues/organs. The expression patterns of many antisense transcripts are conserved across species, suggesting selective pressure on these transcripts. When compared to protein-coding genes, antisense transcripts show a lesser degree of expression conservation. We also found a positive correlation between the sense and antisense expression across tissues.
  
  
  CONCLUSIONS
  Our results suggest that natural antisense transcripts are subjected to selective pressure but to a lesser degree compared to sense transcripts in mammals.
authors.affiliation: Department of Mathematics and Statistics, South Dakota State University, Brookings, SD 57007, USA.
authors.forename: Maurice H T
authors.initials: MH
authors.lastname: Ling
authors.forename: Yuguang
authors.initials: Y
authors.lastname: Ban
authors.forename: Hongxiu
authors.initials: H
authors.lastname: Wen
authors.forename: San Ming
authors.initials: SM
authors.lastname: Wang
authors.forename: Steven X
authors.initials: SX
authors.lastname: Ge
mesh_terms: D000818:Animals; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons / Q000235:genetics; D020869:Gene Expression Profiling; D006801:Humans; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis / Q000379:methods; D009928:Organ Specificity; D016372:RNA, Antisense / Q000235:genetics*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic
chemical_list: D018076:DNA, Complementary; D016372:RNA, Antisense