PMID- 6089182
OWN - NLM
STAT- MEDLINE
DCOM- 19841003
LR  - 20190501
IS  - 0027-8424 (Print)
IS  - 1091-6490 (Electronic)
IS  - 0027-8424 (Linking)
VI  - 81
IP  - 16
DP  - 1984 Aug
TI  - Chromosomal organization of the human dihydrofolate reductase genes: dispersion, 
      selective amplification, and a novel form of polymorphism.
PG  - 5170-4
AB  - 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.
FAU - Anagnou, N P
AU  - Anagnou NP
FAU - O'Brien, S J
AU  - O'Brien SJ
FAU - Shimada, T
AU  - Shimada T
FAU - Nash, W G
AU  - Nash WG
FAU - Chen, M J
AU  - Chen MJ
FAU - Nienhuis, A W
AU  - Nienhuis AW
LA  - eng
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - EC 1.5.1.3 (Tetrahydrofolate Dehydrogenase)
RN  - EC 3.1.21.- (DNA Restriction Enzymes)
SB  - IM
MH  - Animals
MH  - Base Sequence
MH  - Cell Line
MH  - Chromosome Mapping
MH  - Chromosomes, Human, 4-5
MH  - Cricetinae
MH  - DNA Restriction Enzymes
MH  - *Gene Amplification
MH  - *Genes
MH  - Humans
MH  - Hybrid Cells/enzymology
MH  - Lymphocytes/enzymology
MH  - Mice
MH  - *Polymorphism, Genetic
MH  - Tetrahydrofolate Dehydrogenase/*genetics
PMC - PMC391659
EDAT- 1984/08/01 00:00
MHDA- 1984/08/01 00:01
PMCR- 1985/02/01
CRDT- 1984/08/01 00:00
PHST- 1984/08/01 00:00 [pubmed]
PHST- 1984/08/01 00:01 [medline]
PHST- 1984/08/01 00:00 [entrez]
PHST- 1985/02/01 00:00 [pmc-release]
AID - 10.1073/pnas.81.16.5170 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 1984 Aug;81(16):5170-4. doi: 10.1073/pnas.81.16.5170.