A sequence of nucleotides in DNA that resembles a functional gene but is not transcribed. Pseudogenes are thought to arise by duplication of an existing gene through unequal crossing-over during meiosis, with accompanying loss of the promoter or other flanking regions required for transcription. For example, the α- and β-globin gene clusters in humans contain several pseudogenes. Processed pseudogenes lack promoter and intron sequences and seem to have arisen by reverse transcription of a messenger RNA molecule and insertion of the DNA transcript into the chromosomal DNA.
Subjects: Biological Sciences.