| First Author | Dush MK | Year | 1983 |
| Journal | J Cell Biol | Volume | 97 |
| Pages | 134a (Abstr.) | Mgi Jnum | J:12031 |
| Mgi Id | MGI:60291 | Citation | Dush MK, et al. (1983) Analysis of a processed APRT pseudogene. J Cell Biol 97:134a (Abstr.) |
| abstractText | Full text of Abstract: 134a Gene Structure (486-516). 506. Analysis of a Processed APRT Pseudogene. M.K. Dush, S.A. Khan*, J.M. Sikela*, J.A. Tischfield and P.J. Stambrook, Department of Anatomy and Cell Biology. University of Cincinnati Medical Ctr., Cincinnati, OH, and Department of Anatomy, Medical College of Georgia, Augusta, GA. We have used a cloned gene encoding mouse APRT as a probe for Southern blot analysis of genomic mouse DNA. After EcoRI digestion, there is a major band of hybridization at l4kb and two weakly hybridizing bands at 3.0 and 1.8kb. Digestion with PvuII produces intense bands of hybridization at 1.3 and 1.8kb and weak bands at 12 and 14kb. Intense bands represent hybridization to the endogenous functional gene, whereas production of weak bands is consistent with hybridization to pseudogenes that have diverged from the functional sequence. We have recovered a recombinant lambda clone (lambda-Map15) that hybridizes with the functional APRT gene, but which is incapable of conferring an Aprt+ phenotype upon aprt- cells by DNA-mediated transfection. Digestion of lambda-Map15 DNA with EcoRI and with PvuII produces restriction fragments that hybridize to an APRT DNA probe and which have a size of 3.0 and 12 kb respectively. These sizes correspond to the size of weakly hybridizing genomic bands after digestion with the same enzymes. We have subcloned the EcoRI 3.0 kb fragment into pBR328 (designated p15), and have localized those sequences homologous to the APRT gene. The nucleotide sequence of the homologous region has been determined and compared with that of the functional gene. This comparison reveals: 1) Homology between p15 and the coding region of the functional gene is about 80 percent; 2) Mutations in p15 include transitions, transversions, point deletions and a 12bp deletion; 3) The four known introns, characteristic of the functional gene, have been precisely removed so that the homologous region of p15 is co-linear with an APRT cDNA; 4) The 5' end of p15 is truncated in that it does not extend to the 5' end of the APRT transcriptional unit. We conclude that the APRT DNA sequence we have isolated represents a processed APRT pseudogene that may have arisen by reverse transcription and subsequent insertion of an APRT mRNA, or by transposition following incorporation into a retrovirus. Supported by NSF PCM 8118283. |
