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B F Brandriff

Publications and source records attributed to B F Brandriff.

17 recordsLinked to original sources
PubMed1995

Human nicotinamide N-methyltransferase gene: molecular cloning, structural characterization and chromosomal localization.

Genomic DNA clones for nicotinamide N-methyltransferase (NNMT), an enzyme that catalyzes drug and xenobiotic metabolism, were isolated from a human chromosome 11-specific DNA library. Study of one of those clones, when combined with PCR-based experiments performed with human genomic DNA, made it possible to determine the structure of the human NNMT gene. The gene was approximately 16.5 kb in length and consisted of 3 exons and 2 introns. Transcription initiation for the NNMT gene occurred 105-109 nucleotides 5'-upstream from the cDNA translation initiation codon on the basis of the results of both primer extension and 5'-rapid amplification of cDNA ends. NNMT mapped to chromosome band 11q23.1 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed1995

Human estrogen sulfotransferase gene (STE): cloning, structure, and chromosomal localization.

Sulfation is an important pathway in the metabolism of estrogens. We recently cloned a human liver estrogen sulfotransferase (EST) cDNA. We have now determined the structure and chromosomal localization of the EST gene, STE, as a step toward molecular genetic studies of the regulation of EST in humans. STE spans approximately 20 kb and consists of 8 exons, ranging in length from 95 to 181 bp. The locations of most exon-intron splice junctions within STE are identical to those found in a human phenol ST (PST) gene, STM, and in a rat PST gene. In addition, the locations of five STE introns are also conserved in the human dehydroepiandrosterone (DHEA) ST gene, STD. The 5'-flanking region of STE contains one CCAAT and two TATA sequences. The location of one of the TATA box elements is in excellent agreement with the site of transcription initiation as determined by 5'-rapid amplification of cDNA ends. STE was mapped to human chromosome 4q13.1 by fluorescence in situ hybridization. Cloning and structural characterization of STE will now make it possible to study potential molecular genetic mechanisms involved in the regulation of EST in human tissues.

Amino Acid Sequence↗
PubMed1995

High-resolution genetic and physical mapping of multiple epiphyseal dysplasia and pseudoachondroplasia mutations at chromosome 19p13.1-p12.

Multiple epiphyseal dysplasia (MED) and pseudoachondroplasia (PSACH) are autosomal dominant chondrodysplasias that have similar phenotypes at both clinical and cytological levels. With the recent mapping of PSACH and one form of MED (EDM1) to the pericentromeric region of chromosome 19, it is likely that the disease mutations are allelic. D19S212 and D19S215, genetic markers flanking the EDM1/PSACH locus, have been localized in a chromosome 19 physical map consisting of cosmid contigs ordered by high-resolution FISH. These two markers define an interval of approximately 3.1 Mb at the 19p13.1-p12 boundary. With as many as five informative crossovers within the D19S212-D19S215 interval in one family with EDM1 and one family with a mild form of PSACH, recombination mapping at greater resolution was undertaken. From cosmid contigs physically mapped within the D19S212-D19S215 interval, four new dinucleotide repeat polymorphisms have been identified. Analysis of recombinant haplotypes in the two families has narrowed the possible location of the EDM1/PSACH gene to an interval of approximately 600 kb.

Base Sequence↗
PubMed1994

Human chromosome 19p: a fluorescence in situ hybridization map with genomic distance estimates for 79 intervals spanning 20 Mb.

A physical map of human chromosome 19p has been constructed by fluorescence in situ hybridization of cosmids to metaphase chromosomes and sperm pronuclear interphases. The map spans approximately 20 Mb and was generated with 141 multiple, partially overlapping estimates of genomic distances for 79 intervals separating 80 sequentially ordered cosmid reference points. The average distance separating pairs of cosmids was 250 kb, with a range from 50 to 700 kb; 75% of the intervals were estimated to be less than or equal to 300 kb and only 8 intervals were between 500 and 700 kb. Cosmids positive for 33 genes or gene families and 5 polymorphic markers were included among the mapped elements. The fluorescence in situ hybridization map will be useful for furthering the integration of the physical and genetic maps of 19p and for placing newly identified markers within a few hundred kb of their neighbors.

Analysis of Variance↗
PubMed1994

Chromosomal damage in sperm of patients surviving Hodgkin's disease following MOPP (nitrogen mustard, vincristine, procarbazine, and prednisone) therapy with and without radiotherapy.

Following fusion with hamster eggs, human sperm chromosomes from six Hodgkin's disease patients were analyzed to determine the genotoxic effects of therapy. Each patient had received two to six cycles of MOPP (nitrogen mustard, vincristine, procarbazine, and prednisone), with or without radiotherapy, from 3 to 20 years before the study. A total of 571 cells from the six patients were analyzed; 9.8% of the cells had structural aberrations, and 1.6% were hyperhaploid. Analysis of 5998 metaphases from a control group of 24 male donors revealed only 6.9% of cells with structural aberrations and 0.8% aneuploidy. The increase in hyperhaploidy in the patients was statistically significant. Thus, results of this study suggest that the MOPP regimen, with or without radiotherapy, is capable of causing chromosome abnormalities in the sperm of Hodgkin's disease patients.

Adolescent↗
PubMed1993

Evidence for human meiotic recombination interference obtained through construction of a short tandem repeat-polymorphism linkage map of chromosome 19.

An improved linkage map for human chromosome 19 containing 35 short tandem repeat polymorphisms (STRPs) and one VNTR (D19S20) was constructed. The map included 12 new (GATA)n tetranucleotide STRPs. Although total lengths of the male (114 cM) and female (128 cM) maps were similar, at both ends of the chromosome male recombination exceeded female recombination, while in the interior portion of the map female recombination was in excess. Cosmid clones containing the STRP sequences were identified and were positioned along the chromosome by fluorescent in situ hybridization. Four rounds of careful checking and removal of genotyping errors allowed biologically relevant conclusions to be made concerning the numbers and distributions of recombination events on chromosome 19. The average numbers of recombinations per chromosome matched closely the lengths of the genetic maps computed by using the program CRIMAP. Significant numbers of chromosomes with zero, one, two, or three recombinations were detected as products of both female and male meioses. On the basis of the total number of observed pairs of recombination events in which only a single informative marker was situated between the two recombinations, a maximal estimate for the rate of meiotic STRP "gene" conversion without recombination was calculated as 3 x 10(-4)/meiosis. For distances up to 30 cM between recombinations, many fewer chromosomes which had undergone exactly two recombinations were observed than were expected on the basis of the assumption of independent recombination locations. This strong new evidence for human meiotic interference will help to improve the accuracy of interpretation of clinical DNA test results involving polymorphisms flanking a genetic abnormality.

Base Sequence↗
PubMed1992

Spatial distribution of sperm-derived chromatin in zygotes determined by fluorescence in situ hybridization.

Fluorescence in situ hybridization was used to determine the spatial distribution of chromatin in zygote pronuclei. A hybrid system involving golden hamster eggs and individual human sperm permitted use of DNA probes specific for the entire human chromosome 4, for the heterochromatic region on the long arm of the human Y chromosome and for unique DNA sequences on human chromosome 19. Chromosome 4 occupied a circumscribed domain in the pronuclei, similar to findings in somatic interphases. Unlike the situation in somatic interphases, the Y heterochromatin was extended throughout the first cell cycle. Pronuclear chromatin was extended 3- to 4-fold compared to somatic interphase chromatin. The extended pronuclear chromatin conformation is likely to affect a zygote's susceptibility to environmental hazards.

Animals↗
PubMed1992

Order and genomic distances among members of the carcinoembryonic antigen (CEA) gene family determined by fluorescence in situ hybridization.

Fluorescence in situ hybridization was used to establish the order of, and to estimate genomic distances among, members of the carcinoembryonic antigen (CEA) and pregnancy-specific glycoprotein (PSG) subgroups on chromosome 19. Fluorescence in situ hybridization to metaphase chromosomes localized the PSG subgroup telomeric to the CEA subgroup. Cosmid clones containing sequences for individual genes in the CEA and PSG subgroups were also hybridized to human sperm pronuclear and somatic interphase nuclear chromatin targets. The mapping results lead to the gene order cen-CGM7-CEA-NCA-CGM1-BGP-CGM9-CGM8-PSG-te l. The genomic distances between selected pairs of gene family members were estimated from the physical distances between hybridization sites measured in pronuclei. The CEA-PSG gene family region is estimated to span 1.1 to 1.2 Mb.

Carcinoembryonic Antigen↗
PubMed1991

DNA sequence mapping by fluorescence in situ hybridization.

Various types of DNA probes, such as total genomic DNA, repetitive sequences, unique sequences, and composites of chromosome-specific DNA probes, can be used with fluorescence in situ hybridization (FISH) techniques to address research questions having to do with localization, mapping, and distribution of DNA in situ. FISH involves the formation of a heteroduplex between such DNA probes and chromatin targets on a microscope slide, which can be visualized with fluorescent reporter molecules. Three chromatin targets--metaphase chromosomes, somatic interphases, and zygote interphases--offer increasingly extended states of chromatin which can be strategically selected, individually or in combination, to address specific research questions of interest.

Chromosome Mapping↗
PubMed1991

The male-derived genome after sperm-egg fusion: spatial distribution of chromosomal DNA and paternal-maternal genomic association.

After fusion with an egg, the haploid genome of a mammalian sperm expands from a volume of a few cubic microns to a volume of several thousand cubic microns in a fully developed zygote pronucleus. Using fluorescent in situ hybridization we studied two aspects of the chromatin organization of the sperm-derived genome during this process in a model system involving fusion of human sperm with hamster eggs. We found that (a) from the beginning of sperm head decondensation to early pronuclear stages, the hybridization signal of a probe targeted to the satellite III heterochromatin of chromosome 1 appeared as an irregularly shaped domain. In fully developed pronuclei, the signal became a fiber as much as 20-fold more extended compared with interphase somatic nuclei. The signal appeared as a string of non-uniformly distributed "beads" with interspersed gaps. A similar spatial distribution and appearance recurred after the first cleavage division. (b) Male- and female-derived genomes assembled non-randomly on the first mitotic spindle, and continued to be sequestered from each other in the nuclei of two-cell stages.

Animals↗
PubMed1989

Analysis of the first cell cycle in the cross between hamster eggs and human sperm.

Golden hamster eggs fused with human sperm were pulsed with bromodeoxyuridine to determine the timing of S-phase and the length of the first cell cycle in this hybrid cross. Fused eggs were fixed and pronuclei scored for incorporation of the thymidine analogue detected by indirect immunofluorescence. Although S-phase started synchronously 3-3.5 hr after coincubation of sperm and eggs, its duration was variable such that two-cell stages appeared at 16 hr while a proportion of pronuclei was still engaged in DNA synthesis. Unlike rodent sperm chromatin, human sperm chromatin was able to participate in DNA synthesis well before its maturation into a fully developed pronucleus. Human sperm chromatin appears able to function under conditions different in several respects from those in human eggs.

Animals↗
PubMed1988

Chromosomal aberrations induced by in vitro irradiation: comparisons between human sperm and lymphocytes.

Types and frequencies of structural aberrations in human sperm and lymphocyte chromosomes from one donor were compared after in vitro irradiation with 100, 200, and 400 rad in order to determine if cells with dramatically different chromatin configurations are similarly affected and to investigate the feasibility of using lymphocytes as surrogates for germ cells in risk estimation. Sperm chromosomes were analyzed after fusion with eggs from the golden hamster. Total frequencies of induced aberrations were similar in the two cell types. However, the relative frequencies of rejoined lesions (dicentrics), compared with unrejoined lesions (chromosome breaks and acentric fragments), were different. At the three doses tested, a constant ratio of 5 dicentrics in lymphocytes for every dicentric in sperm was induced. Conversely, for every chromosome break or acentric fragment induced in lymphocytes, 1.7 such events were induced in sperm at the three doses tested.

Chromosome Aberrations↗
PubMed1988

An analysis of structural aberrations in human sperm chromosomes.

We have analyzed structural aberrations in 5,000 sperm chromosome complements obtained from 20 men over a 5-yr period by fusion of human sperm with hamster eggs. Detailed data are presented on 366 abnormal cells with 379 analyzable breakpoints. The frequency of cells with structural aberrations ranged from 1.9% to 14.5% among donors; this interindividual variability was statistically significant (p less than 0.0001). In contrast, repeat samples from individual men showed no significant variation over time. The number of sperm chromosome sets processed per hamster egg had no effect on the frequency with which structural aberrations occurred, nor were sperm chromosome abnormalities altered by varying capacitation or culture conditions. The spectrum of structural aberrations observed in human sperm chromosomes and a chi-square analysis of breakpoints based on DNA content are presented. Although human sperm chromosome abnormalities were visualized with a cross-species system, we believe that they represent an inherent, biologically significant phenomenon.

Animals↗
PubMed1986

Sex chromosome ratios determined by karyotypic analysis in albumin-isolated human sperm.

Human sperm that had been processed for Y-enrichment (male sex preselection) according to a currently favored albumin density gradient procedure were analyzed karyotypically for the proportion of X and Y chromosomes with the use of the human sperm/hamster egg system. This method allows direct inspection of haploid chromosome complements from human sperm. In 290 albumin-isolated sperm from six men, there were 57.2% X- and 42.8% Y-bearing chromosome complements; 201 unprocessed concurrent control sperm from five of the men had 50.2% X and 49.8% Y complements. The observed shift in sex chromosome ratio in processed samples, a decrease in Y-bearing sperm, was not statistically different from that of unprocessed controls (P = 0.13) but was significantly different when compared with the theoretic X/Y ratio of 50/50 (P = 0.016). A total of 3187 historical control karyotypes were also reviewed, with an overall sex chromosome ratio (X/Y) of 49.8/50.2. The control groups did not differ significantly from the expected 50/50. The Y-enrichment of processed sperm was not confirmed.

Animals↗
PubMed1986

The chromosomal constitution of human sperm selected for motility.

The chromosome constitutions of sperm selected for motility according to the swim-up technique were compared cytogenetically with those of sperm remaining in the semen with the use of the human sperm/hamster egg system, in which human sperm are fused with hamster eggs to give analyzable haploid chromosome complements. Three semen samples from one donor resulted in 153 chromosome complements from selected, highly motile sperm and 110 unselected, control complements. Four samples were donated by another man, from which 181 selected and 186 control complements were obtained. The frequencies of chromosomal aberrations recovered from the population selected for high motility and the unselected population were not statistically different from one another.

Animals↗