title: Uncovering information on expression of natural antisense transcripts in Affymetrix MOE430 datasets.
abstract: BACKGROUND
  The function and significance of the widespread expression of natural antisense transcripts (NATs) is largely unknown. The ability to quantitatively assess changes in NAT expression for many different transcripts in multiple samples would facilitate our understanding of this relatively new class of RNA molecules.
  
  
  RESULTS
  Here, we demonstrate that standard expression analysis Affymetrix MOE430 and HG-U133 GeneChips contain hundreds of probe sets that detect NATs. Probe sets carrying a "Negative Strand Matching Probes" annotation in NetAffx were validated using Ensembl by manual and automated approaches. More than 50 % of the 1,113 probe sets with "Negative Strand Matching Probes" on the MOE430 2.0 GeneChip were confirmed as detecting NATs. Expression of selected antisense transcripts as indicated by Affymetrix data was confirmed using strand-specific RT-PCR. Thus, Affymetrix datasets can be mined to reveal information about the regulated expression of a considerable number of NATs. In a correlation analysis of 179 sense-antisense (SAS) probe set pairs using publicly available data from 1637 MOE430 2.0 GeneChips a significant number of SAS transcript pairs were found to be positively correlated.
  
  
  CONCLUSIONS
  Standard expression analysis Affymetrix GeneChips can be used to measure many different NATs. The large amount of samples deposited in microarray databases represents a valuable resource for a quantitative analysis of NAT expression and regulation in different cells, tissues and biological conditions.
authors.affiliation: Institute of Medical Microbiology, Immunology and Hygiene Technical University Munich, Munich, Germany. sebastian.oeder@lrz.tum.de <sebastian.oeder@lrz.tum.de>
authors.forename: Sebastian
authors.initials: S
authors.lastname: Oeder
authors.forename: Joerg
authors.initials: J
authors.lastname: Mages
authors.forename: Paul
authors.initials: P
authors.lastname: Flicek
authors.forename: Roland
authors.initials: R
authors.lastname: Lang
mesh_terms: D000465:Algorithms; D000818:Animals; D002874:Chromosome Mapping / Q000379:methods*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D005821:Genetic Techniques; D023281:Genomics / Q000379:methods*; D006801:Humans; D051379:Mice; D008957:Models, Genetic; D020411:Oligonucleotide Array Sequence Analysis; D016376:Oligonucleotides, Antisense / Q000235:genetics*; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016376:Oligonucleotides, Antisense; D012333:RNA, Messenger; D012313:RNA