Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.4.2.8 (hypoxanthine-guanine phosphoribosyltransferase)
 2,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chinese hamster X mouse somatic cell hybrids segregating mouse chromosomes were examined for their mouse chromosome content using trypsin-Giemsa (GTG) banding and Hoechst 33258 staining techniques. Simultaneously, they were scored for the presence of 24 mouse enzymes. The results confirm the assignments of 11 genes previously mapped by sexual genetics: Dip-1 and Id-1 to chromosome 1; Pgm-2 and Pgd to 4; Pgm-1 to 5; Gpi-1 to 7; Gr-1 to 8; Mpi-1 and Mod-1 to 9; Np-1 and Es-10 to 14. They also confirm chromosomally the assignments of 3 genes that were made by other somatic cell genetic studies: Aprt to 8; Hprt and alpha-gal to the X chromosome. But most importantly, four enzyme loci are assigned to four chromosomes that until now were not known to carry a biochemical marker which is expressed in cultured cells: Trip-1 to 10; Dip-2 to 18; Acp-1 to 12; and Ak-1 to 2. Cytogenetic examination of clones showing discordant segregation of HPRT and A-GAL, suggested the assignment of alpha-gal to region XE leads to XF of the mouse X chromosome. The cytologic studies provide a comparison between data from sexual genetics and somatic cell hybrids and validate hybrid cell techniques. They provide evidence of the reliability of scoring chromosomes by GTG and Hoechst staining and stress the importance of identifying clones with multiple chromosome rearrangements. Striking examples of norandom segregation of mouse chromosomes were observed in these hybrids with preferential retention of 15 and segregation of 11 and the Y chromosome.
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PMID:Gene mapping in Mus musculus by interspecific cell hybridization: assignment of the genes for tripeptidase-1 to chromosome 10, dipeptidase-2 to chromosome 18, acid phosphatase-1 to chromosome 12, and adenylate kinase-1 to chromosome 2. 19 84

A hybrid cell line (R21/B1) containing a truncated human chromosome 6 (6pter-6q21) and a human Y chromosome on a hamster background was irradiated and fused to A23 (TK-) or W3GH (HPRT-) hamster cells. Clones containing expressed HLA class I genes (4/40) were selected using monoclonal antibodies. These clones were recloned and analyzed with a panel of probes from the HLA region. One hybrid (4G6) contained the entire HLA complex. Two other hybrids (4J4 and 4H2) contained only the HLA class I region, while the fourth hybrid (5P9) contained HLA class I and III genes in addition to other genes located in the 6p21 chromosomal region. In situ hybridization showed that the hybrid cells contained more than one fragment of human DNA. Alu and LINE PCR products were derived from these cells and compared to each other as well as to products from two somatic cell hybrids having the 6p21 region in common. The PCR fragments were then screened on conventional Southern blots of the somatic cell hybrids to select a panel of novel probes encompassing the 6p21 region. In addition, the origin of the human DNA fragments in hybrid 4J4 was determined by regional mapping of PCR products.
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PMID:Isolation of probes specific to human chromosomal region 6p21 from immunoselected irradiation-fusion gene transfer hybrids. 190 83

The sensitivity of small transgenes to position effects on their expression suggests that they could serve as indicators of the chromatin properties at their integration site. In particular, they might be expected to provide information on the functional properties of mammalian heterochromatin. We have produced a transgenic line that carries a mouse Hprt minigene on the Y chromosome. In situ hybridization localized the transgene to the heterochromatic portion of the Y. Analysis of transgene expression by isoelectric focusing indicated that the transgene is expressed in a mosaic pattern, and expressing cells have different levels of transgene activity. These findings can be explained as a position effect variegation induced by Y heterochromatin. However, two other transgenes, located at autosomal sites, also showed mosaic activity. If the mosaic transgene expression is attributed to the influence of the chromatin at the insertion site, the Y heterochromatin would appear less potent than some autosomal regions at inducing variegation. An alternative explanation consistent with our results is that the mosaic expression is a semi-autonomous characteristic of these transgene loci. Transgene-expressing and non-expressing cells differed in their ability to grow and be cloned in vitro, indicating that cellular differentiation affected the chromatin structure of the transgene locus on the Y. Karyotype analysis of male mice with the Y-linked transgene and from control male mice carrying the human HPRT transgene, or the mouse Pgk-1 gene at autosomal sites, indicated that the transgene-carrying Y is prone to non-disjunction, generating cells with two (or more) or no Y chromosomes in equal proportion. Further studies will determine if the propensity of this Y chromosome to mitotic errors is also observed in vivo.
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PMID:Mosaic expression of an Hprt transgene integrated in a region of Y heterochromatin. 817 60

Quantitative fluorescent polymerase chain reaction (QF-PCR) assays and small tandem repeat (STR) markers have been successfully employed for the rapid detection of major numerical aneuploidies affecting human autosomes. So far, the analysis of chromosomes X and Y disorders has been hampered by the rarity of highly polymorphic markers which could distinguish normal female homozygous PCR patterns from those seen in patients with Turner's syndrome. A new marker (X22) of the X/Y chromosomes has been identified which maps in the Xq/Yq pseudoautosomal region PAR2; used together with the HPRT it allows the rapid diagnosis of numerical aneuploidies of the sex chromosomes. Blood samples from normal male and female subjects and from patients with X and Y chromosome disorders (45,X and 47, XXY) have been tested by QF-PCR with the X22 polymorphic pentanucleotide (12 alleles) together with the HPRT and P39 markers. The samples were also tested by multiplex QF-PCR with STRs specific for chromosomes 21,18,13 and amelogenin (AMXY). Tested by QF-PCR, all samples from normal females were heterozygous for either the X22 or the HPRT marker with fluorescent peak ratios near 1:1, thus allowing a correct, rapid diagnosis of their chromosome complement. Turner's patients (45,X) showed only one X22 and one HPRT fluorescent peak, thus documenting the presence of a single X chromosome. Turner's patients with mosaicism showed a major fluorescent peak for the X22 and HPRT markers and a minor peak revealing the presence of a second minor population of cells. Two 47, XXY cases could also be diagnosed. Multiplex analyses can be performed using simultaneously STR markers for chromosomes 21,18,13 X and Y. The diagnostic value of a third X-linked marker (P39) was also investigated. These results suggest that rapid diagnosis of major numerical anomalies of the X and Y chromosomes can be performed using QF-PCR with a new highly polymorphic X-linked marker, X22, which maps in the Xq/Yq pseudoautosomal region PAR 2. Multiplex QF-PCR tests-using the X22 STR in association with HPRT and, in rare cases, a third P39 marker-allow the rapid diagnosis of major aneuploidies affecting chromosomes 21, 18, 13, X and Y. The X22 marker can also be employed for the detection of fetal cells present in maternal peripheral blood or the endocervical canal.
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PMID:Rapid detection of chromosomes X and Y aneuploidies by quantitative fluorescent PCR. 1059 Apr 24