Transcription of a human dopamine D5 pseudogene

We have previously reported that the human genome contains the two pseudogenes psi DRD5-1, and psi DRD5-2, and that each share 94% homology when compared with the functional gene DRD5. There is only 2% difference at the nucleotide level between the two pseudogenes. We questioned whether these pseudogenes were transcribed, since transcription of either of these pseudogenes could result in false interpretation of in-situ hybridization and Northern blot analysis, using the DRD5 as a probe. We now report that we have detected transcription of one of the pseudogenes, psi DRD5-1, in several human brain areas, and this mRNA transcript is capable of producing a protein of 154 amino acids. Furthermore we report that PCR amplification of DRD5 or the pseudogenes in human tissue can result in the formation of chimer artifacts due to the co-amplification of three very similar genes.