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Biomedical subjects

J Womack

Publications and source records attributed to J Womack.

At least 19 recordsLinked to original sources
PubMed2003

The river buffalo (Bubalus bubalis, 2n = 50) cytogenetic map: assignment of 64 loci by fluorescence in situ hybridization and R-banding.

Sixty-four genomic BAC-clones mapping five type I (ADCYAP1, HRH1, IL3, RBP3B and SRY) and 59 type II loci, previously FISH-mapped to goat (63 loci) and cattle (SRY) chromosomes, were fluorescence in situ mapped to river buffalo R-banded chromosomes, noticeably extending the physical map of this species. All mapped loci from 26 bovine syntenic groups were located on homeologous chromosomes and chromosome regions of river buffalo and goat (cattle) chromosomes, confirming the high degree of chromosome homeologies among bovids. Furthermore, an improved cytogenetic map of the river buffalo with 293 loci from all 31 bovine syntenic groups is reported.

Animals↗
PubMed2002

A comparative map of bovine chromosome 25 with human chromosomes 7 and 16.

A comparative genome map is necessary for the implementation of comparative positional candidate gene cloning in cattle. We have developed a medium density comparative gene map of bovine chromosome 25 (BTA25). A radiation hybrid (RH) panel was used to map nine microsatellites and nine genes. Eight of the nine comparative loci were also mapped by FISH. These results were combined with data from published articles to create a comprehensive comparative map of BTA25 with human chromosomes 7 (HSA7) and 16 (HSA16). This map should facilitate the cloning of genes of interest on bovine chromosome 25.

Animals↗
PubMed2001

Isolation of lumenal proteins from spinach thylakoid membranes by triton X-114 phase partitioning.

The proteins present in the thylakoid lumen of higher plant chloroplasts have not been rigorously examined. In this communication we present a simple and rapid procedure for the isolation of the soluble proteins and extrinsic membrane proteins present in the thylakoid lumen from spinach. Our procedure involves extensive washing of the thylakoid membranes followed by Triton X-114 phase partitioning. When analyzed by one-dimensional polyacrylamide gel electrophoresis (PAGE), we obtain results which are very similar to those obtained by Kieselbach et al. using more classical methods [T. Kieselbach, A. Hagman, B. Andersson, W.P. Schroder, J. Biol. Chem. 273 (1998) 6710-6716]. About 25 major proteins are observed upon Coomassie blue staining. Upon two-dimensional isoelectric focusing-sodium dodecyl sulfate-PAGE and either Coomassie blue or silver staining, however, numerous other protein components are resolved. Our findings indicate that the total number of proteins (soluble and extrinsic membrane) present in the lumen may exceed 150.

Detergents↗
PubMed2000

Comparative gene mapping workshop: progress in agriculturally important animals.

Following the successful Comparative Mapping Workshop held at Fraser Island, Australia in 1995, HUGO organized a second workshop of 41 invited participants, held at Toulouse, France on May 3 and 4, 1999. The aim of the conference was to focus on recent developments in genome mapping in a variety of vertebrate species, with particular emphasis on progress in farm animals (cattle, pigs, chickens, sheep, horses, goats, and deer). In addition, representatives from important experimental mammalian and vertebrate organisms (e.g. mice, rats, dogs, fugu, and marsupials) also participated in the meeting. After a rapid overview of developments in the construction and comparison of genome maps in a wide variety of species, discussion focused on how comparative genomics will play a vital role in the genetic dissection of multigenic traits and the characterization of agriculturally important loci in agricultural species. Acceleration of gene discovery with heterologous ESTs (Expressed Sequence Tags) or collections of ESTs was discussed. Recent developments in the construction of cDNA libraries and the efficiency of tools such as whole genome radiation hybrids (RH) and large fragment clone libraries (YACs and in particular BACs) were discussed. Proposed criteria to improve the identification of homologous genes between species and recommendations for nomenclatures were identified. Particular emphasis was placed on how the integration of biological databases could help the scientific community.

Agriculture↗
PubMed1996

Microsatellite mapping of the bovine roan locus: a major determinant of White Heifer disease.

In the Belgian Blue Cattle breed, coat color variation is mainly under the influence of a single autosomal locus, the roan locus, characterized by a pair of codominant alleles: r+ (black) and R (white). Heterozygous r+R animals have intermingled black and white hairs, yielding the "blue" phenotype typical of the breed. Major interest for the roan locus stems from its pleiotropic effect on fertility, owing to the critical role of the R allele in the determinism of White Heifer Disease. We describe the linkage mapping of the roan locus to bovine Chromosome (Chr) 5, in the interval between microsatellite markers BPI and AGLA293, with an associated lodscore of 11.2. Moreover, we map a candidate gene, the Steel locus coding for the mast cell growth factor, to bovine Chr 5.

Animals↗
PubMed1994

Sequence of the coding region of the bovine fibrillin cDNA and localization to bovine chromosome 10.

We report the cDNA sequence for the bovine gene for fibrillin corresponding to the human gene, fibrillin 1 (FBN1), and the localization of the gene to bovine chromosome 10 (syntenic group U5). The identity between the human and bovine sequences is 97.8% at the amino acid level and 92% at the nucleotide level. The bovine fibrillin sequence contains the same number and type of motifs as the human FBN1 sequence, including the same number of putative calcium binding sites. All of the motifs conform to the patterns demonstrated in the human sequence, and many of the differences in identity between the sequences are conservative.

Amino Acid Sequence↗
PubMed1994

Chromosomal localization and detection of DNA polymorphisms in the bovine polymeric immunoglobulin receptor gene.

Polymeric immunoglobulin receptor (PIGR) mediates transcellular transport of secretory antibodies in glandular and mucosal epithelial cells. By use of a bovine-rodent somatic cell hybrid panel the bovine PIGR locus has been assigned to syntenic group U1. Using in situ hybridization, PIGR was localized to bovine chromosome 16, segment q13, thus confirming the recent assignment of syntenic group U1 to this chromosome. Two common restriction fragment length polymorphisms (RFLPs) with the enzymes BamHI and MspI were detected using the PIGR cDNA as probe. Direct PCR sequencing of a segment in the PIGR coding region (nucleotides 162-413) from 13 bulls of Norwegian Cattle revealed single nucleotide exchanges at two positions. An efficient PCR-RFLP method for detection of these mutations was developed.

Animals↗
PubMed1993

Construction of a bovine genomic library of large yeast artificial chromosome clones.

We have constructed a yeast artificial chromosome (YAC) library derived from bull fibroblasts in primary culture. The library consists of 21,500 clones arranged on 224 gridded plates (96 or 8 x 12 positions) and in 2 x 224 96-well microplates maintained as permanent frozen stocks. An average insert size of 750 kb was estimated from the analysis of 200 randomly selected YACs, giving a sixfold coverage of the bovine genome for the total library. A screening strategy based on the polymerase chain reaction that allows the identification of individual clones has been devised. Screening of the library with six locus-specific markers of interest led to the isolation of 34 positive clones. The proportion of chimeric YACs was estimated from the analysis of a subset of the positive clones: 3 of 9 YACs were found to contain noncontiguous DNA.

Animals↗
PubMed1990

Effects of cytochrome P-450 monooxygenase inducers on mouse hepatic microsomal metabolism of testosterone and alkoxyresorufins.

The effects of treatment with phenobarbital, 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), pregnenolone-16 alpha-carbonitrile (PCN), 3-methylcholanthrene (3-MC) and isosafrole on the hepatic microsomal formation of nine monohydroxy metabolites of testosterone and the O-dealkylation of the ethyl and pentyl ethers of resourfin were evaluated in adult male C57BL/6J and DBA/2NCR mice. In both strains, phenobarbital, TCPOBOP and PCN induced testosterone 2 beta-, 6 beta-, 15 beta- and 16 beta-hydroxylases up to 5-fold, while phenobarbital and TCPOBOP increased the rate of dealkylation of pentoxyresorufin by approximately 30-fold. However, phenobarbital and TCPOBOP did not exhibit identical patterns of induction for the testosterone oxidation reactions. Hepatic microsomes from C57BL/6J mice treated with TCPOBOP displayed a depression in 6 alpha-testosterone hydroxylase activity, which was also observed in PCN-treated animals, whereas phenobarbital-treated mice exhibited an elevation in this monooxygenase activity. A dose of TCPOBOP (0.5 mumol/kg) previously demonstrated to represent an ED50 for mouse aminopyrine N-demethylase activity was also found to approximate the ED50 for pentoxyresorufin O-dealkylase activity in the C57BL/6J mouse. Isosafrole or 3-MC treatment had little effect on testosterone metabolism or pentoxyresorufin O-dealkylase activity in either strain, while 3-MC induced ethoxyresorufin O-deethylase activity in C57BL/6J but not DBA/2NCR mice. This study confirms that TCPOBOP is a potent cytochrome P-450 inducer which most closely resembles phenobarbital in its mode of action. However, TCPOBOP and phenobarbital do not evoke identical modulations of cytochrome P-450-dependent monooxygenases in mice.

Animals↗
PubMed1989

Induction of glutathione S-transferases in genetically inbred male mice by dietary ethoxyquin hydrochloride.

1. Constitutive and ethoxyquin hydrochloride (EQ-HCl)-induced hepatic glutathione (GSH) S-transferase, GSH reductase, and GSH peroxidase activities were determined in 5 strains of 8-10 week old inbred male mice. 2. The constitutive GSH S-transferase (GST) activity varied from 2.9 (SJL/JCR) to 8.9 (C57BL/6NCR) mumol product formed/min/mg protein and the corresponding values for the EQ-HCl-treated mice were in the range of 15.3-25.3 mumol product formed/min/mg protein. 3. EQ-HCl induced GST activity in all the strains examined and this contrasted to the induction activity of Aroclor 1254 which was strain-dependent. GST activity was induced 2.9-fold in Aroclor 1254-responsive (C57BL/6) and 2.8-fold in non-responsive (DBA/2) mice, respectively.

Animals↗