Chromosomal organization of the human dihydrofolate reductase genes: dispersion, selective amplification, and a novel form of polymorphism
| العنوان: | Chromosomal organization of the human dihydrofolate reductase genes: dispersion, selective amplification, and a novel form of polymorphism |
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| المؤلفون: | Arthur W. Nienhuis, Nicholas P. Anagnou, Stephen J. O'Brien, Mann-Jy Chen, Takashi Shimada, William G. Nash |
| المصدر: | Proceedings of the National Academy of Sciences. 81:5170-5174 |
| بيانات النشر: | Proceedings of the National Academy of Sciences, 1984. |
| سنة النشر: | 1984 |
| مصطلحات موضوعية: | Pseudogene, Locus (genetics), Hybrid Cells, Biology, Cell Line, Mice, Gene mapping, Cricetinae, Gene duplication, Gene cluster, Animals, Humans, Gene family, Chromosomes, Human, 4-5, Lymphocytes, Gene, Genetics, Polymorphism, Genetic, Multidisciplinary, Base Sequence, Gene Amplification, Chromosome Mapping, DNA Restriction Enzymes, Tetrahydrofolate Dehydrogenase, genomic DNA, Genes, Research Article |
| الوصف: | The human dihydrofolate reductase (DHFR; tetrahydrofolate dehydrogenase; 5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) gene family includes a functional gene (hDHFR) and at least four intronless genes. Three intronless genes (hDHFR-psi 2, hDHFR-psi 3, and hDHFR-psi 4) are identifiable as pseudogenes because of DNA sequence divergence from the functional gene with introns, while one intronless gene (hDHFR-psi 1) is completely homologous to the coding sequences of the functional gene. Analysis of genomic DNA from two panels of somatic human-rodent cell hybrids with specific molecular probes provide insight into the chromosomal organization and assignment of these genes. The five genes are dispersed in that each one is found on a different chromosome. The functional gene hDHFR has been assigned to chromosome 5, and one pseudogene (hDHFR-psi 4), to chromosome 3. In a human cell line (HeLa) that was selected for methotrexate resistance, the functional locus became amplified, while there was no amplification of the four intronless pseudogenes. hDHFR-psi 1 was found to be present in DNA of some individuals and absent from DNA of others, consistent with a recent evolutionary origin of this gene originally suggested by its sequence identity to the coding portions of the functional gene. The presence or absence of this intronless pseudogene represents a previously unreported form of DNA polymorphism. |
| تدمد: | 1091-6490 0027-8424 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7384cb905e54095ff596dc642bb022cf https://doi.org/10.1073/pnas.81.16.5170 |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....7384cb905e54095ff596dc642bb022cf |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 10916490 00278424 |
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