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Biomedical subjects

R W Elliott

Publications and source records attributed to R W Elliott.

At least 37 records · Page 2Linked to original sources
PubMed1997

Expression and chromosomal mapping of mouse Gpx2 gene encoding the gastrointestinal form of glutathione peroxidase, GPX-GI.

GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI contributes to at least fifty percent of GPX activity in rodent small intestinal epithelium. The total GPX activity consists of at least 70% of selenium-dependent GPX activity in this compartment. By analyzing a panel of mouse interspecies DNA from the Jackson Laboratory's backcross resource, we mapped Gpx2 gene to mouse chromosome 12 between D12Mit4 and D12Mit5, near the Ccs1 locus which contains a colon cancer susceptibility gene. A pseudogene, Gpx2-ps is mapped to mouse chromosome 7. Comparison of Gpx2 gene expression in three pairs of C57BL/6Ha and ICR/Ha mice which are respectively resistant and sensitive to dimethylhydrazine-induced colon cancer, we found a higher Gpx2 mRNA level in C57BL/6Ha colon than ICR/Ha colon. Interestingly, a lower level of GPX activity is found in the resistant strain of mice. Because GPX-1 has three times higher specific activity than GPX-GI, our data suggest that the decreased GPX activity may result from a higher level of Gpx2 gene expression in those cells co-express Gpx1 gene.

Amino Acid Sequence↗
PubMed1996

Fine mapping of the human and mouse genes for the type I procollagen COOH-terminal proteinase enhancer protein.

The human gene (PCOLCE) for the C-proteinase enhancer, a glycoprotein that enhances the enzymatic activity that cleaves the type I procollagen C-propeptide, was previously mapped to the same cytogenetic region (7q21.3-q22) as COL1A2, the type I collagen pro-alpha 2 chain gene. The apparent proximity of these two genes, whose products interact, might have reflected some mechanism for coregulation of expression. We have employed somatic cell hybrids, cosmid contigs, and interspecific backcross mice to investigate further the apparent proximity of the two genes. Our data show that PCOLCE and COL1A2 are separated by at least 6 Mb on human chromosome 7q and that Pcolce and Col1a2 are located on two separate chromosomes in mouse. These data also indicate that PCOLCE is located within a 10- to 15-cM region of conserved synteny between human chromosome 7 and mouse chromosome 5.

Animals↗
PubMed1995

A genomic clone containing a telomere array maps near the centromere of mouse chromosome 6.

A lambda clone of mouse DNA containing a short array of telomere hexamers has been localized by FISH to a region close to the centromere of Chromosome (Chr) 6. Amplification of DNA with primers flanking an SSR showed that most inbred strains carry one of two alleles, although five other alleles were found among the inbred strains and 11 other alleles were found in wild-derived mice. Analysis of the DNA from four Robertsonian translocations suggests that the amplified sequence is still present in these chromosomes. The finding of two fragments associated with the Sig mutant suggests that the clone lies within a congenic region created when the mutant, obtained in a (C3H x 101)F1, was backcrossed to C57BL/6J. This region might include all or part of the centromere. Comparison of the segregation of the amplification product with the segregation of centromeric heterochromatin in an interspecies backcross, (C57BL/6 x M. spretus)F1 x M. spretus, (BSS) shows 1/72 recombinants with the centromeric heterochromatin, while 1/62 recombinants occurred in a BSB backcross. Analysis of other loci at the proximal end of Chr 6 gives the combined map Hc6-0.73-D6Mit86-0.73-D6Rp2-2.2-D6Mitl-2.2-Wn t2-3.0-Cpa. Data from a third cross show that Cola2 lies between D6Mit82 and D6Rp2. The portion of the telomere array, Tel-rs3, that has been sequenced contains only 13/31 repeats of the consensus sequence. A variety of sequence changes from the consensus hexamer suggests that this array has been removed for a long time from evolutionary pressures to retain the TTAGGG sequence.

Animals↗
PubMed1994

Genetic analysis of colon cancer susceptibility in mice.

Mouse models may aid in the identification of genes involved in colon cancer. Our mating scheme involved mouse strains selected for maximum differences in susceptibility to DMH-induced colon tumors. Tumors were found in 40 of 122 progeny from a backcross to the resistant strain. We examined progeny animals for segregation of 177 genetic markers distributed at intervals of 5-30 cM on all mouse chromosomes. Multiple loci contribute to the phenotype, with significant linkage to a novel locus, Ccs1, between D12Mit5 and D12Mit6 on mouse Chr 12. Comparative maps suggest that the human homologue of Ccs1 is near FOS on human chromosome 14q.

1,2-Dimethylhydrazine↗
PubMed1994

Reproducibility of the centric relation bite registration technique.

Many orthodontists today are using diagnostic casts mounted in centric relation (CR) because they can reveal a completely different malocclusion than what is seen in maximum intercuspation (MI). The CR to MI slide can be measured at the condyles using a semi-adjustable articulator and a condylar position indicator device (CPI). However, before planning treatment from casts mounted in CR, the reliability of the method must be established. Therefore, the purposes of this investigation were: i) to determine the reproducibility, measured with the CPI, of the two-piece wax CR bite registration technique as described by Roth; ii) to determine the direction of the centric slide; iii) to determine differences in overjet measured from CR and MI and; iv) to evaluate the location of the initial tooth contacts in CR. The condylar displacements for 39 subjects were measured in vertical and horizontal components from mounted models. A CR bite registration was taken five times (approximately every five days) and used to remount the lower cast and record the data five times. Since there was not a significant difference between the five CPI readings (p > .05), the Roth CR bite registration is highly reproducible. The condyle moved inferiorly with a small distal component from CR to MI. A statistically significant difference (p < .001) was found in the overjet measurements between CR and MI. Thirty six out of 39 subjects had an initial tooth contact in CR on the most posterior tooth.

Adult↗
PubMed1993

Localization of the murine activating transcription factor 4 gene to mouse chromosome 15.

Restriction fragment length variant analysis employing a mouse cDNA probe was used to localize the gene encoding murine activating transcription factor 4 (ATF-4) to mouse chromosome 15 in close proximity to Sis (the cellular homolog of the simian sarcoma virus oncoprotein). Previous studies suggest that conserved linkage relationships exist between this region of mouse chromosome 15 and human chromosome 22q. The chromosomal locations of genes encoding most members of the ATF and cyclic AMP response element binding protein (CREB) subfamily of b-zip proteins have not been determined. This study demonstrates that the location of the gene for murine ATF-4 is not linked to the genes for JUN family members, CREB1 and CREB2. Further mapping of individual ATF/CREB subfamily members in the mouse will provide insight into the evolution of this multigene family.

Activating Transcription Factor 4↗
PubMed1993

Linkage of Agt and Actsk-1 to distal mouse chromosome 8 loci: a new conserved linkage.

Angiotensinogen is an alpha 2-globulin involved in the maintenance of blood pressure and electrolyte balance. We have refined the position of the mouse angiotensinogen locus (Agt) on Chromosome (Chr) 8 and have also confirmed the assignment of the human angiotensinogen locus (AGT) to Chr 1. The segregation of several restriction fragment length variants (RFLVs) was followed in two interspecific backcross sets and in four recombinant inbred (RI) mouse sets. Analysis of the segregation patterns closely linked Agt to Aprt and Emv-2, which places the angiotensinogen locus on the distal end of mouse Chr 8. Additionally, a literature search has revealed that the strain distribution pattern (SDP) for the mouse skeletal alpha-actin locus 1 (Actsk-1, previously Acta1, Acta, or Acts) is nearly identical to the SDP for Agt in two RI sets. On the basis of this information we were able to reassign Actsk-1 to mouse Chr 8. By screening a panel of human-mouse somatic cell hybrids, we confirmed that the human angiotensinogen locus lies on Chr 1. This information describes a new region of conserved linkage homology between mouse Chr 8 and human Chr 1. It also defines the end of a large region of conserved linkage homology between mouse Chr 8 and human Chr 16.

Actins↗
PubMed1993

Chromosomal assignment of the recoverin gene and cancer-associated retinopathy.

The deduced amino acid sequence of the recently cloned mouse 23kD photoreceptor cell-specific protein showed it to be identical to the recoverin protein and the CAR (cancer-associated retinopathy) protein. DNA sequence variants were found in the mouse recoverin gene (Rcvrn), and segregation analysis of restriction fragment length variants in recombinant inbred strains of mice assigned Rcvrn to mouse Chromosome (Chr) 11, between Sparc (3.7 map units) and Zfp-3 (2.3 map units). These results demonstrate a close linkage of recoverin to the tumor suppressor gene, Trp53. On the basis of these data, knowledge of the function of recoverin, and the characteristics of CAR, an experimentally testable model is presented to explain the molecular basis for CAR.

Animals↗
PubMed1993

Characterization of murine middle repetitive DNA.

We have characterized four sequences from a small library containing a subset of the repetitive families of the mouse. Each clone has a repetition frequency of less than 1,100 copies per genome and each clone represents a unique family of middle repetitive DNA. One clone (pMR111) shares homology with mouse intracisternal A-particle (IAP) elements, a second clone (pMR89) has partial homology with a sequence in the 3' untranslated region of the human fibulin gene, while two clones (pMR6, pMR66) are new that have no homology to any reported DNA sequence. Each clone hybridizes to one or two discrete RNA transcripts from one or more tissues of the mouse. Clone pMR66 detected restriction fragment length polymorphisms (RFLPs) at three loci in genomic mouse DNA, defining loci at the distal end of chromosome 5 and the proximal end of chromosome 7. The third locus is unmapped. This study demonstrates that cloned repeats from a repetitive DNA library are a potential source of genetic markers.

Amino Acid Sequence↗
PubMed1992

Deletion mapping of the mouse ornithine decarboxylase-related locus Odc-rs8 within Igh-V.

The Odc-rs8 locus belongs to a family of mouse DNA sequences related to the gene encoding ornithine decarboxylase (ODC). Odc-rs8 was mapped by recombinant inbred (RI) strain analysis to the region of Chromosome (Chr) 12 occupied by the variable region genes of the immunoglobulin heavy chain (Igh) complex. In the present study, alleles at Odc-rs8 were shown to cosegregate with those for Igh variable region (Igh-V or VH) genes among 37 inbred mouse strains that had been characterized previously for their haplotypes at Igh. For a more precise definition of the location of Odc-rs8 relative to Igh-V, DNAs from 17 Abelson murine leukemia virus (A-MuLV)-transformed pre-B cell lines cultured from mice heterozygous at Igh and Odc-rs8 were analyzed for the presence of DNA restriction fragments (RFs) derived from each parental Odc-rs8 allele. These cell lines, each of which has rearranged one or both Igh genes, previously were employed in mapping members of nine VH gene families by deletion analysis (Brodeur et al. 1988). Comparing the deletion profiles of the cell lines for Odc-rs8 with those for the VH gene families has located Odc-rs8b within the VHJ558/VH3609 gene cluster and Odc-rs8c either within or upstream of the 5'-most 9% of VHJ558, identifying Odc-rs8 as a potentially useful marker for the 5' end of the Igh complex.

Alleles↗
PubMed1992

Mapping of the mouse ornithine decarboxylase-related sequence family.

A family of DNA sequences homologous to the mRNA encoding ornithine decarboxylase (ODC) and comprising approximately 12 members in the mouse genome has been analyzed genetically. The inheritance of variant DNA restriction fragments detected by ODC cDNA probes on Southern blots of DNA from inbred strain mice was determined in six sets of recombinant inbred (RI) mouse strains. The distributions of these variations among the RI strains were then compared with the RI strain distribution patterns (SDPs) of previously mapped loci. This allowed the identification of nine independent ODC-related loci, of which eight could be localized to specific regions of the mouse genome: Odc-rs1 near Lamb2 on Chromosome (Chr) 1; Odc-rs2 near Psp on Chr 2; Odc-rs5, a complex locus comprising at least 5-7 copies of the ODC sequence, associated with Igk on Chr 6; Odc-rs6 between Abpa and Tam-1 on proximal Chr 7; Odc-rs7 near Hbb on distal Chr 7; Odc-rs12 near Agt and Emv-2 on distal Chr 8; Odc-rs8 associated with the Igh complex on Chr 12; and Odc-rs9 near Otf-3f on Chr 14. The ODC-related sequence family thus comprises a set of genomically dispersed "marker" loci, and alleles for several of these loci can be analyzed simultaneously in DNA from mice or cell lines. DNA from mice of 70 inbred strains has been characterized for alleles at all nine Odc-rs loci.

Alleles↗
PubMed1992

Genetic mapping of two DNA markers, D16Ros1 and D16Ros2, flanking the mutation site in the chakragati mouse, a transgenic insertional mutant.

We present here the genetic mapping of two novel loci, D16Ros1 and D16Ros2, to mouse Chromosome (Chr) 16. The probes for these loci were genomic fragments isolated from the chakragati mouse, a behavioral mutant resulting from insertional mutagenesis during the course of making transgenic mice. D16Ros1 and D16Ros2 were first mapped by recombinant inbred (RI) strain analysis and subsequently by the analysis of 145 progeny of two interspecific backcrosses between Mus domesticus and Mus spretus. These progeny had been typed for the centromere and this allowed mapping of D16Ros1 and D16Ros2 relative to the centromere. The other markers included in this study were Prm-1, Gap43 and Sod-1. The genetic map generated spanned 47.5 cM from the centromere to Sod-1, the most distal marker mapped here. The linkage data presented here should prove useful in mapping other loci relative to the centromere of Chr 16.

Animals↗
PubMed1992

Fine-structure mapping of the complex locus Odc-rs5 relative to Igk and distal loci.

Odc-rs5 was previously identified as a complex locus closely linked to the Igk complex on mouse Chromosome (Chr) 6 and comprising at least five copies of a sequence related to the mRNA encoding ornithine decarboxylase (ODC) in the genomes of mice of some inbred strains and at least seven copies in others (Richards-Smith and Elliott, Mammalian Genome 2: 215, 1992). In the present study, Odc-rs5 was shown to be composed of at least seven copies of the ODC sequence in both the Odc-rs5a and Odc-rs5b haplotypes. Based upon the distribution of DNA restriction fragments (RFs) that had previously been associated with Odc-rs5a or Odc-rs5b among 42 mice of inbred laboratory strains having various haplotypes at Igk and in mice of two congenic strains [B6.PL-Ly-2a, Ly-3a(75NS)/Cy and B6.PL-Ly-2a,Ly-3a(85NS)/Cy] and a backcross-derived stock (NAK) known to be recombinant within Igk, a fine structure map of Odc-rs5 was deduced relative to Igk and more distal loci. Odc-rs5-derived RFs were located to three distinct regions within and/or distal to Igk and to a fourth site between (Ly-3, Ly-2) and Raf-1. Additionally, DNAs from 19 mice of inbred strains and random-bred stocks derived from wild progenitors trapped at various locations were analyzed and found to exhibit an unexpected variety of combinations of RFs associated with the two Odc-rs5 haplotypes most frequently observed among inbred laboratory strains of mice.

Animals↗