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F T Kao

Publications and source records attributed to F T Kao.

At least 73 records · Page 4Linked to original sources
PubMed1985

Regional mapping of the phenylalanine hydroxylase gene and the phenylketonuria locus in the human genome.

Phenylketonuria (PKU) is an autosomal recessive disorder of amino acid metabolism caused by a deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH; phenylalanine 4-monooxygenase, EC 1.14.16.1). A cDNA clone for human PAH has previously been used to assign the corresponding gene to human chromosome 12. To define the regional map position of the disease locus and the PAH gene on human chromosome 12, DNA was isolated from human-hamster somatic cell hybrids with various deletions of human chromosome 12 and was analyzed by Southern blot analysis using the human cDNA PAH clone as a hybridization probe. From these results, together with detailed biochemical and cytogenetic characterization of the hybrid cells, the region on chromosome 12 containing the human PAH gene has been defined as 12q14.3----qter. The PAH map position on chromosome 12 was further localized by in situ hybridization of 125I-labeled human PAH cDNA to chromosomes prepared from a human lymphoblastoid cell line. Results of these experiments demonstrated that the region on chromosome 12 containing the PAH gene and the PKU locus in man is 12q22----12q24.1. These results not only provide a regionalized map position for a major human disease locus but also can serve as a reference point for linkage analysis with other DNA markers on human chromosome 12.

Chromosome Mapping↗
PubMed1985

Assignment of the gene for human sphingolipid activator protein-2 (SAP-2) to chromosome 10.

Sphingolipid activator protein-2 (SAP-2) has been found to stimulate the enzymatic hydrolysis of glucosylceramide, galactosylceramide, and sphingomyelin. When human skin fibroblast extracts were subjected to sodium dodecylsulfate-polyacrylamide gel electrophoresis followed by electroblotting and immunochemical staining using monospecific antibodies against SAP-2, two or three major bands with estimated mol. wts. of 9,000-10,000 were found. These antibodies did not crossreact with purified SAP-1, another activating protein, or with extracts of CHO-K1 cells. A series of 22 human/Chinese hamster ovary cell hybrids containing different human chromosomes were examined by this method. All eight hybrid clones containing human chromosome 10 were found to have crossreacting protein in this region. Other chromosomes could be excluded by this method. From these results, we conclude that the gene coding for human SAP-2 is located on chromosome 10.

Animals↗
PubMed1984

Human apolipoprotein A-II: nucleotide sequence of a cloned cDNA, and localization of its structural gene on human chromosome 1.

Using the technique of oligonucleotide hybridization, we have isolated two dscDNA clones to human apolipoprotein A-II. One of the clones (pAII-1) has been completely sequenced. It has 433 nucleotides which includes a poly A tail of 10 adenylic acid residues, all the coding and 3'-non-translated regions of the mRNA and part of the 5'-non-translated region. The amino acid sequence derived from the cDNA clone includes 100 amino acids (including the 23 amino acid prepropeptide) which is very similar to the sequence reported by Brewer et al. (Proc. Natl. Acad. Sci. USA 69, 1304-1308). [32P]-labeled pAII-1 was used as a probe in chromosome mapping studies to detect the human apoAII structural gene sequence in human-Chinese hamster cell hybrids. Southern blot analysis of 10 hybrids localized the gene to human chromosome 1.

Amino Acid Sequence↗
PubMed1984

High-resolution chromosome sorting and DNA spot-blot analysis assign McArdle's syndrome to chromosome 11.

A rapid gene-mapping system uses a high-resolution, dual-laser sorter to identify genes from separate human chromosomes prepared with a new stain combination. This system was used to sort 21 unique chromosome types onto nitrocellulose filter papers. Several labeled gene probes hybridized to the sorted chromosomal DNA types predicted by their previous chromosome assignments. The skeletal muscle glycogen phosphorylase gene was then mapped to a portion of chromosome 11 by spot blotting normal and translocated chromosomes.

Animals↗
PubMed1984

Localization of the structural gene for human apolipoprotein A-I on the long arm of human chromosome 11.

Apolipoprotein A-I (apo A-I), the major apolipoprotein in human high density lipoproteins, is involved in the disease atherosclerosis. Cloned apo A-I cDNA (pA1-3) was used as a probe in chromosome mapping studies to detect the human apo A-I structural gene sequence in human-Chinese hamster cell hybrids. Southern blot analysis of 13 hybrids localized the gene to human chromosome 11. Confirmation of the chromosomal assignment was obtained by analysis of a hybrid (J1) containing a single human chromosome, no. 11. Regional mapping was achieved by using deletion subclones of J1 that localized the human apo A-I structural gene to the region 11q13 leads to qter. Since the human apolipoprotein C-III (apo C-III) structural gene is closely linked to apo A-I, it can be assigned to the same region on the long arm of chromosome 11. By extension of methods previously described, it now appears possible to carry out fine-structure analysis of this and related gene regions on chromosome 11 and to study the biochemical concomitants of these genes and of genes on other chromosomes for analysis of their role in atherosclerosis.

Animals↗
PubMed1983

Assignment of the alpha 1-antitrypsin gene and a sequence-related gene to human chromosome 14 by molecular hybridization.

alpha 1-Antitrypsin is a major plasma protease inhibitor synthesized in the liver. Genetic deficiency of this protein predisposes the affected individuals to development of infantile liver cirrhosis or chronic obstructive pulmonary emphysema. The human chromosomal alpha 1-antitrypsin gene has been cloned and shown to contain three introns in the peptide-coding region. When the cloned alpha 1-antitrypsin gene was used as a hybridization probe to analyze Eco RI-digested genomic DNA from different individuals, two distinct bands of 9.6 kilobases (kb) and 8.5 kb in length were observed in every case. Further analysis using only labeled intronic DNA as the hybridization probe has indicated that the authentic alpha 1-antitrypsin gene resides within the 9.6-kb fragment. Thus the 8.5-kb fragment must contain another gene that is closely related in sequence to the alpha 1-antitrypsin gene. Using a series of human-Chinese hamster somatic cell hybrids containing unique combinations of human chromosomes, the alpha 1-antitrypsin gene as well as the sequence-related gene have been assigned to human chromosome 14 by Southern hybridization and synteny analysis.

Animals↗
PubMed1982

Assignment of the structural gene coding for albumin to human chromosome 4.

Albumin is a developmentally regulated serum protein synthesized in the liver mainly during adulthood. Family studies using variant forms of albumin established autosomal linkage between albumin and group-specific component protein (GS). Since GC has been assigned to human chromosome 4, albumin can be indirectly assigned to the same chromosome; however no direct assignment has been made. Recently, the human albumin cDNA probe has been isolated and characterized. It thus permits a direct chromosomal assignment of the albumin gene in the human genome. When the cDNA probe was hybridized to the HindIII digested total human DNA, an intense band at 6.8 kb was present. When the probe was hybridized to the HindIII digested Chinese hamster CHO-K1 DNA, a less intense band at 3.5 kb was found, plus three other faint bands. When the probe was hybridized to a series of human/CHO-K1 cell hybrids retaining a complete hamster genome and various combinations of human chromosomes, it was evident that hybrids containing human albumin gene sequences could be readily distinguished from hybrids containing no human albumin gene. Analysis of 22 primary cell hybrids for the presence or absence of human albumin sequences has assigned the albumin gene to human chromosome 4. Similar results were obtained using another restriction endonuclease EcoR1. Thus, by direct assay of the genomic albumin gene sequences in the cell hybrids, we provide evidence for a direct assignment of the structural gene for human albumin to chromosome 4.

Albumins↗
PubMed1982

Isolation of a human repetitive sequence and its application to regional chromosome mapping.

Recombinant lambda phage Charon 4A with repetitive human DNA inserts have been constructed by using cellular DNA from a human-Chinese hamster ovary cell hybrid retaining the complete hamster genome and a single human chromosome 12. One recombinant phage, 12-11, contains several repetitive sequences, each with a different repetition pattern in the human genome. A 2.2-kilobase (kb) EcoRI fragment of this phage was subcloned in pBR325. This sequence has fewer than 5,000 copies in the human genome and does not cross-hybridize with Chinese hamster DNA. When the labeled 2.2-kb probe was hybridized to human chromosome 12 DNA digested with EcoRI, there was an intense band at the 2.2-kb position and a series of other discrete bands. The band pattern at positions other than 2.2 kb appears to be distinct for each human chromosome. The 2.2-kb fragment is composed of at least three subregions. The ends of the fragment are repeated more frequently in the genome than is the middle portion. Hybridization of chromosome 12 DNA with probes made to these subregions yielded simpler band patterns. By using a series of cell hybrids containing various deletions of human chromosome 12, five sequences related to the 2.2-kb fragment have been assigned regionally to a specific portion of the short arm of chromosome 12. These results demonstrate that certain repetitive sequences in the human genome can be used as genetic markers and may permit detailed regional mapping of human chromosomes.

Animals↗
PubMed1982

Genetic fine-structure mapping in human chromosome 11 by use of repetitive DNA sequences.

A method is described for mapping of the DNA fragments of a human chromosome produced by restriction enzyme treatment of the total DNA from a hybrid cell containing a single human chromosome. The method involves production and selection of somatic cell mutants containing deletions of the human chromosome and application of a hybridization probe consisting of an individual member copy of a repetitive human DNA family. A linear map has been constructed of 19 marker DNA fragments and 5 immunological and biochemical markers on human chromosome 11, selected as a model chromosome for these studies. This approach appears to be widely applicable, is independent of cytogenetic analysis, promises to be capable of revealing the existence of rearrangements as well as deletions, appears to be amenable to further increase in resolving power, and offers potential application in various human genetic problems.

Cell Line↗
PubMed1982

Isolation and chromosomal localization of unique DNA sequences from a human genomic library.

Recombinant bacteriophage lambda from a human genomic library were screened to indentify human DNA inserts having only unique sequences. Unique human inserts were found in about 1% of the phage screened. One recombinant phage, P3-2, was studied in detail. It contains a human insert of 14.7 kilobases with four internal EcoRI cleavage sites. A restriction map was constructed for EcoRI and BamHI sites. Hybridization of the 32P-labeled P3-2 probe to a Southern blot of EcoRI-digested total human DNA yielded distinct bands at positions corresponding to the human insert fragments contained in P3-2. By using a series of human-Chinese hamster somatic cell hybrids containing unique combinations of human chromosomes, the human DNA segment in phage P3-2 was assigned to human chromosome 22 by blot hybridization and synteny analysis. In addition, another human DNA segment, 11.4 kilobases, in phage P3-10 was assigned to human chromosome 10 by similar procedures. With this approach, more unique DNA sequences can be isolated, assigned to specific human chromosomes, and used as genetic markers for gene mapping and linkage, polymorphism, and other genetic studies in the human genome.

Animals↗
PubMed1982

Regional mapping of the gene coding for enolase-2 on human chromosome 12.

Enolase-2 (ENO2), previously termed 14-3-2 protein, is an isozyme of enolase that is enriched in neuronal tissue. The gene coding for ENO2 was previously assigned to human chromosome 12. The present study presents data for a regional mapping of gene ENO2 using cell hybrids containing various deletions of human chromosome 12. These deletions were produced by treatment with chromosome-breaking agents. Cytogenetic analysis has allowed assignment of ENO2 to the short arm of chromosome 12, in the region of pter-p1205. This assignment is consistent with the segregation pattern of the 93 hybrid clones analysed. The segregation pattern has also established the linear order of 6 genes on chromosome 12:pter-TPI-GAPD-LDHB-ENO2-centromere-SHMT-PEPB-qter. Estimation of the relative distances between the 6 genes on chromosome 12 has been made by a statistical mapping analysis of the segregation data of the hybrid clones. A set of deletion hybrids containing various combinations of these 6 markers has been established for a rapid regional mapping of genes in one of these regions on chromosome 12.

Animals↗
PubMed1981

Assignment of the gene coding for phosphoribosylglycineamide formyltransferase to human chromosome 14.

Purine-requiring Chinese hamster ovary cell auxotrophs of the complementation class ade-E were hybridized with various human cells, and hybrids were isolated under selective conditions in which the retention of the complementing gene on the human chromosome is necessary for survival. Synteny analysis in 72 primary and secondary hybrid clones using isozyme, karyotypic, and biochemical methods provides evidence for an assignment of the gene for phosphoribosylglycineamide formyltransferase (GART, EC 2.1.2.2), deficient in ade-E mutants, to human chromosome 14. The importance of this gene assignment to the development of hypotheses regarding the organization, structure, and regulation of genes involved in the same biosynthetic pathway in mammalian cells is discussed.

Acyltransferases↗
PubMed1980

Expression of genes coding for non-histone chromosomal proteins in human-Chinese hamster cell hybrids. An electrophoretic analysis.

The non-histone chromosomal (NHC) proteins of several human and hamster cell lines as well as human-hamster cell hybrids were investigated by one- and two-dimensional gel electrophoresis. In each type of human cell, over 90% of the 230 most prominent NHC proteins were indistinguishable electrophoretically from the NHC proteins of the hamster cells. Of the roughly 10% which were distinct, 11 of the proteins may be human-specific, since they were found in each type of human cell examined. The NHC proteins in seven different stable human-hamster cell lines, which, in total, contained markers for 21 of the 24 human chromosomes, were electrophoretically indistinguishable from those of the parental hamster cell line, with the exception of a single protein in one hybrid line. It is concluded that many of the genes coding for the apparently human-specific NHC proteins are not expressed in these hybrid cells. The single exception to this appeared to be a gene coding for a protein of roughly 300,000 daltons. This protein was synthesized in one of the hybrids, as well as in each type of human cell. Since the NHC proteins of the hybrid and hamster cells were virtually identical, there was no evidence for the expression of genes coding for NHC proteins characteristic of the differentiated state of the parental human cells.

Animals↗
PubMed1980

Isolation and localization of DNA segments from specific human chromosomes.

Recombinant DNA techniques have been combined with somatic cell genetic methods to identify, isolate, and amplify fragments of human DNA localized at specific regions of human chromosome 11 selected as a model system. A library of genomic DNA segments has been constructed, in lambda Charon 4A bacteriophage, from the DNA of a somatic cell hybrid carrying a portion of human chromosome 11 on a Chinese hamster ovary cell background. Using a nucleic acid hybridization technique that distinguishes human and Chinese hamster interspersed, repetitive DNA, we have been able to distinguish recombinant phages carrying DNA segments of human origin from recombinant phages carrying DNA segments of Chinese hamster origin. We have isolated 50 human DNA segments thus far and have characterized 5 in detail. For each DNA segment characterized, a subsegment that carries no repetitive human DNA sequences has been identified. These segments have been used as hybridization probes in experiments that localize the DNA fragment on the chromosome. In each case an unequivocal chromosomal localization has been obtained with reference to a panel of hybrid cell clones each of which carries a deletion of a portion of the short arm of chromosome 11. At least one DNA segment has been identified which maps to each of the four regions on the short arm defined by the panel of hybrid cell clones used. The approaches described here appear to be general. They can be extended to produce a fine structure map of human chromosome 11 and other human chromosomes. This approach promises implications for human genetics generally, for the human genetic diseases, and possibly for understanding of gene regulation in normal and abnormal differentiation.

Animals↗