Generation of processed pseudogenes in murine cells.
Using as a reporter gene a non-coding proviral structure marked with an intron-containing indicator, we demonstrate the de novo formation, via a retrotransposition pathway, of canonical processed pseudogenes in cultured mammalian cells. Their structural features include endings corresponding to the start and termination of the RNA intermediate, intron loss, acquisition of a 3' poly(A) tail, and target site duplications of variable length. The absence of extracellular intermediates for these processes, and the elimination during retrotransposition of sequences in the reporter gene essential in cis for a retroviral cycle, further suggest that endogenous retroviruses or related elements are not involved. Pseudogene formation frequency is markedly increased (up to 10-fold) by several treatments including treatment with 5-azacytidine or tetradecanoyl phorbol acetate, or serum starvation, which do not act at the reporter gene transcription level, but rather on endogenous genes--including the LINE elements--necessarily involved in trans-complementation for retrotransposition.
Tchénio
T
T
Unités de Biochimie-Enzymologie et de Physicochimie Macromoléculaire, CNRS U147, Institut Gustave Roussy, Villejuif, France.
Segal-Bendirdjian
E
E
Heidmann
T
T
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements; D005822:Genetic Vectors; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011544:Pseudogenes; D012367:RNA, Viral / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D012190:Retroviridae / Q000235:genetics
D004251:DNA Transposable Elements; D009838:Oligodeoxyribonucleotides; D012367:RNA, Viral