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Biomedical subjects

J L Hamerton

Publications and source records attributed to J L Hamerton.

At least 37 records · Page 2Linked to original sources
PubMed1989

Chromosomal localization and structure of the human P1 protamine gene.

The human P1 protamine gene and mRNA were amplified with the use of the polymerase chain reaction and cloned into PTZ19R. The sequences were determined which revealed the presence of an intron. Southern and Northern hybridization analyses showed that the gene was single copy and that the mRNA was approximately 450 bases long. The gene was mapped to chromosome 16 with the use of a somatic cell hybrid panel and localized to the 21 region of the q arm by in situ hybridization of the human P1 protamine probe to human metaphase chromosomes.

Amino Acid Sequence↗
PubMed1988

Structural gene encoding human factor XII is located at 5q33-qter.

The gene encoding human factor XII (F12) or Hageman factor has been mapped to 5q33-qter. This has been achieved by analyzing the results obtained from hybridizing a cloned fragment from the factor XII gene to a panel of human-hamster somatic cell hybrid DNAs and also by in situ hybridization to normal human metaphase cells. The previously reported results localizing F12 to 6p23 are discussed.

Animals↗
PubMed1988

Localization of the gene encoding human factor V to chromosome 1q21-25.

The gene encoding human coagulation Factor V (FV), one of the cofactors in the blood clotting process, has been mapped to chromosome 1 by both Southern hybridization to DNA from human-hamster somatic cell hybrids and in situ hybridization. The whole plasmid pUC3A containing a 1.5-kb cDNA sequence for FV was 32P-labeled for Southern analysis and 3H-labeled for in situ hybridization to metaphase chromosomes. The results localized the FV gene to the region of 1q21-25.

Animals↗
PubMed1987

Isolation and characterization of a processed gene for human ceruloplasmin.

A processed pseudogene for human ceruloplasmin has been isolated that contains DNA corresponding to the functional gene sequence encoding the carboxy-terminal 563 amino acid residues and the 3' untranslated region. The pseudogene appears to have arisen from a processed RNA species, since intervening sequences coincident with those of the functional gene have been removed, with the exception of a short segment of intronic sequence which denotes the 5' boundary of the pseudogene. The nucleotide sequence of the pseudogene is highly homologous (97% sequence identity) with that of the wild-type gene, suggesting that pseudogene formation was a relatively recent evolutionary event. In addition to single base substitutions, there is a large 213 base pair (bp) deletion in the pseudogene sequence which corresponds to the location of an intron-exon junction in the functional gene. A 4 bp duplication that occurs at amino acid residue 683 of the wild-type coding sequence results in a frameshift mutation and introduces a premature translational termination codon at this point. This is concordant with the inability to detect a human liver transcript corresponding to the pseudogene by nuclease S1 mapping analysis. The 3' end of the pseudogene is characterized by a 62 bp segment composed mainly of repeated TC dinucleotides. On the basis of genomic Southern blot analysis performed under high-stringency conditions, the pseudogene that we have identified seems to comprise the only sequence in the human genome that is closely related to the wild-type gene. Using somatic cell hybridization, we have mapped the pseudogene to human chromosome 8.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1987

Human genes encoding prothrombin and ceruloplasmin map to 11p11-q12 and 3q21-24, respectively.

The gene for human prothrombin, or factor II (F2) has been assigned to 11p11-q12 by the combined use of a panel of somatic cell hybrid DNAs and in situ hybridization, using both cDNA and genomic probes. In addition, the cDNA probe for F2 recognizes a homologous sequence which has been tentatively mapped to the X chromosome. Similar approaches have been used to confirm the assignment of the ceruloplasmin gene, but to regionally localize it more proximally than previously reported (3q21-q24). These results provide further evidence that genes encoding the coagulation factors and related proteins are dispersed throughout the human genome.

Ceruloplasmin↗
PubMed1987

DNA studies in a family with Duchenne muscular dystrophy and a deletion at Xp21.

We have performed Southern blot analysis on a large, four-generation kindred with Duchenne muscular dystrophy (DMD). Probes 754 (DXS 84), pERT87-1, pERT87-8, pERT87-15 (DXS164), and pXJ-1.1 did not hybridize to digested genomic DNA of affected males. Obligate-carrier mothers and unaffected brothers showed signals of a single X-chromosome copy intensity, and suspected noncarrier sisters demonstrated either a single band of two-copy intensity or informative polymorphisms. Uniform hybridization was seen with probes C7 (DXS28) and D2 (DXS43), which map distal to the DMD locus, and with OTC, which maps proximally. This deletion was present in six affected individuals and has been transmitted through 3 generations to date. On high-resolution chromosome analysis, a deletion within band Xp21 was consistently observed in one affected male studied and in one of the two X chromosomes in obligate carriers. This large molecular and cytogenetically visible deletion in affected DMD individuals without glycerol kinase deficiency, chronic granulomatous disease, retinitis pigmentosa (RP), or ornithine transcarbamylase deficiency is a very rare finding and should prove useful in specifically cloning additional probes within and flanking the DMD locus.

Adolescent↗
PubMed1986

Isolation and characterization of an alpha-satellite repeated sequence from human chromosome 22.

We constructed a library in lambda L47.1 with DNA isolated from flow-sorted human chromosome 22. Over 50% of the recombinants contained the same highly repetitive sequence. When this sequence was used to probe Southern blots of EcoRI-digested genomic DNA, a ladder of bands with increments of about 170 bp was observed. This sequence comigrates with satellite III in Ag+/Cs2SO4 gradients and may account for at least part of the 170 bp Hae III ladder seen in isolated satellite III DNA. Partial sequence analysis revealed homology to the 171 bp monomeric repeat unit of alpha-R1-DNA and the X specific alpha-satellite consensus sequence. After low stringency in situ hybridization, silver grains were found over the centromeres of a number of chromosomes. Under high stringency conditions, however, the labeling was concentrated over the centromeric region of chromosome 22. This localization was confirmed using DNA from a panel of human/hamster cell lines which showed that the homologous 2.1 and 2.8 kb EcoR1 restriction fragments were chromosome 22 specific. These clones therefore contain chromosome 22 derived alpha-satellite sequences analogous to other chromosome-specific satellite sequences described previously.

Animals↗
PubMed1986

The gene for clotting factor 10 is mapped to 13q32----qter.

The structural gene for the human clotting factor 10 (F10) has been mapped to chromosome 13 with a cDNA probe hybridized to DNAs from a panel of human X hamster hybrids. In situ hybridization was used to assign F10 to region 13q32----qter of chromosomes from normal human lymphocytes.

Animals↗
PubMed1986

Regional localization of 18 human X-linked DNA sequences.

A series of human probes with unique sequences has been isolated from a recombinant phage library constructed with DNA obtained from a human-hamster hybrid cell line. This cell line contained the X chromosome as the only human component. For 18 of these probes, a human X-chromosome origin has been confirmed and they have been regionally assigned by a combination of techniques: dosage studies utilizing DNA from human fibroblasts carrying X-chromosome duplications and deletions; the presence or absence of hybridization to digested DNA from hybrid lines carrying fragments of the X chromosome; and in situ hybridization to metaphase chromosomes. The use of dosage as a means to regionally assign probes significantly improves resolution of the X chromosome.

Animals↗
PubMed1985

Chromosomal assignment of human sequences encoding arginine vasopressin-neurophysin II and growth hormone releasing factor.

Complementary DNA clones encoding bovine vasopressin and human pancreas growth hormone releasing factor have been used to map homologous sequences in the human genome. Assignment of both cloned sequences to human chromosome 20 was accomplished by hybridization of insert DNAs to a panel of human-rodent somatic cell hybrids. Both these probes have been used to examine the structure of their respective genes in DNA from various individuals. No restriction fragment variants for growth hormone releasing factor have yet been found. Analysis of populations for restriction fragment length polymorphisms associated with disease states involving arginine vasopressin is underway.

Animals↗
PubMed1982

Analysis of fibroblast proteins from patients with Duchenne muscular dystrophy by two-dimensional gel electrophoresis.

Duchenne muscular dystrophy (DMD), the most common and severe form of the muscular dystrophies, is an X-linked inborn error of metabolism with multiple tissue involvement. Although the major pathological changes are observed in skeletal muscle, abnormalities have also been detected in the heart, nervous system, red blood cells, lymphocytes and cultured skin fibroblasts. For many reasons, such as readily available tissue material, fewer secondary changes and the potential for prenatal diagnosis, cultured skin fibroblasts should be the tissue of choice to search for the primary defect. Several abnormalities have been reported in DMD fibroblasts, suggesting that the genetic abnormality is expressed in these cells. To search for potentially mutant protein(s) we have compared the protein composition of normal and DMD fibroblasts by two-dimensional gel electrophoresis and have now found one protein spot consistently missing in DMD cells. The nature of this protein and its relation to the DMD gene are unknown.

Autoradiography↗