Chimera (EST)

In genetics, a chimera is a single cDNA sequence originating from two transcripts. It is usually considered to be a contaminant in transcript and expressed sequence tag databases.^[1] It is estimated that approximately 1% of all transcripts in the National Center for Biotechnology Information's Unigene database contain a "chimeric sequence".^[2]

Methods have been devised to detect them, such as the Ribosomal Database Project's CHECK_CHIMERA program.^[3] However, in protein engineering, "chimeragenesis (forming chimeras between proteins that are encoded by homologous cDNAs)"^[4] is one of the "two major techniques used to manipulate cDNA sequences".^[4]

Examples

• "The first mRNA transcript isolated for..." the human gene C2orf3 "...was part of an artificial chimera..."
• CYP2C17 was thought to be a human gene, but "...is now considered an artefact based on a chimera of CYP2C18 and CYP2C19."^[5]
• Researchers have created receptor chimeras in their studies of Oncostatin M.

See also

• Transgene

References

1. ^ Unneberg, P; Claverie, JM; Hoheisel, Jörg (2007). "Tentative mapping of transcription-induced interchromosomal interaction using chimeric EST and mRNA data.". PloS one 2 (2): e254. doi:10.1371/journal.pone.0000254. PMC 1804257. PMID 17330142. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1804257. 
2. ^ Charlie Nelson. "EST Assembly for the Creation of Oligonucleotide Probe Targets". Agilent Technologies. http://www.chem.agilent.com/Library/applications/5989_0750_EST_final72.pdf. Retrieved May 12, 2009. 
3. ^ Maidak, B. (1996). "The Ribosomal Database Project (RDP)". Nucleic Acids Research 24 (1): 82. doi:10.1093/nar/24.1.82. http://nar.oxfordjournals.org/cgi/content/full/24/1/82#tbl01. Retrieved May 12, 2009. 
4. ^ ^{a b} Lajtha, Abel; E. A. Reith, Maarten (2007). Handbook of Neurochemistry and Molecular Neurobiology Neural Membranes and Transport. Boston, MA: Springer Science+Business Media, LLC.. pp. 485. ISBN 0387303472.  p. 424
5. ^ "Entrez Gene: CYP2C18 cytochrome P450, family 2, subfamily C, polypeptide 18". National Center for Biotechnology Information. http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1562. Retrieved May 12, 2009.