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M F Seldin

Publications and source records attributed to M F Seldin.

At least 163 records · Page 9Linked to original sources

Single-strand conformational polymorphism (SSCP) mapping of the mouse genome: integration of the SSCP, microsatellite, and gene maps of mouse chromosome 1.

Interspersed repetitive sequence (IRS) PCR and repetitive element-to-bubble (IRS-bubble) PCR have been utilized to rapidly generate large numbers of mouse-specific, chromosome 1-enriched STSs from mouse-hamster somatic cell hybrids. Single-strand conformational polymorphism (SSCP) has been used to localize 39 new repetitive element-linked STSs to the mouse map: 22 to Chr 1, 10 to Chr. 15, 2 each to Chrs 12 and 14, and three to Chr 7. In addition, we have integrated the SSCP, single-strand length polymorphism, and restriction fragment length polymorphism maps of mouse Chr. 1, resulting in a high-density map of the chromosome, containing over 100 loci, all typed on a single interspecific backcross.

Animals↗

Gene structure, chromosomal localization, and protein sequence of mouse CD53 (Cd53): evidence that the transmembrane 4 superfamily arose by gene duplication.

CD53 is a pan-leukocyte surface glycoprotein which spans the plasma membrane four times and is a member of the transmembrane 4 superfamily (TM4SF). The protein sequence and gene structure of mouse CD53 (Cd53) were determined by isolation of both genomic and cDNA clones. CD53 is highly conserved in evolution, as mouse Cd53 was 91% identical to rat CD53 and 82% identical to human CD53. The mouse Cd53 gene spanned approximately 9.0 kb of DNA and encoded the 219 amino acid residues of CD53 over seven exons. The Cd53 gene produced a 1.8 kb transcript which was dramatically upregulated after cell activation. The mouse Cd53 gene was mapped to chromosome 3, whereas the locus of another TM4SF member, CD37 (Cd37), was mapped to mouse chromosome 7. Three lines of evidence suggest that the TM4SF arose divergently from an ancestral gene. First, the gene structure of CD53 was strikingly similar to two other members of the TM4SF, CD63 and TAPA-1; second, Cd37 mapped to the same chromosome as Tapa-1; and, third, Cd37 mapped to a segment of chromosome 7 that contains a number of genes that are structurally or functionally related to genes closely linked to Cd53 on chromosome 3.

Amino Acid Sequence↗

Mapping of the mouse Rar loci encoding retinoic acid receptors RAR alpha, RAR beta and RAR gamma.

Nuclear retinoic acid receptors RAR alpha, RAR beta and RAR gamma are transcription factors that bind all-trans retinoic acid as their ligand and mediate its action by activating particular set of genes that contain retinoic acid responsive elements in their promoter-enhancers. We have mapped genetic loci for these genes using restriction fragment length variants (RFLVs) in interspecific backcross mice. None of the Rar loci cosegregated with each other or with the new subclass of retinoid receptors, Rxr loci. Rara mapped to mChr 11, Rarb mapped to mChr 14, and Rarg mapped to mChr 15. The results are consistent with the previous reports and the human data in terms of syntenic homology between mouse and human chromosomes.

Animals↗

Genetic analysis of MRL-lpr mice: relationship of the Fas apoptosis gene to disease manifestations and renal disease-modifying loci.

In MRL mice, the mostly recessive lpr mutation results in both the accumulation of CD4-, CD8-, CD3+ T cells in lymphoid tissue and many features of generalized autoimmune disease, including immune complex glomerulonephritis. To positionally clone the lpr mutation and analyze the effects of background genes, backcross offspring were examined from the cross: (MRL/MpJ-lpr x CAST/Ei)F1 x MRL/MpJ-lpr. The lpr gene was found to be closely linked to a mouse chromosome 19 marker defined by a variation of a Fas gene restriction fragment. Our results identified differences in RNA expression and differences in the genomic organization of the Fas gene between normal and lpr mice, and confirm the recent report that a mutation in the Fas apoptosis gene is the lpr mutation. However, our results also indicate that the Fas gene is expressed in spleen cells from normal mice, and spleen and lymph node cells from mice with a second mutation at the lpr locus (lprcg). Together these results suggest that altered Fas transcription results in the failure of lymphocytes to undergo programmed cell death and may lead to an altered immune cell repertoire. This mechanism may explain certain central and peripheral defects in tolerance that are present in autoimmune disease. The current study also demonstrates the profound effect of background genes on the degree of nephritis, lymphadenopathy, and anti-DNA antibody production. Of major note, our studies suggest the identification of chromosomal positions for genes that modify nephritis. Analysis of the backcross mice for markers covering most of the mouse genome suggests that over 50% of the variance in renal disease is attributable to quantitative trait loci on mouse chromosomes 7 and 12. Moreover, this study provides a model for dissecting the complex genetic interactions that result in manifestations of autoimmune disease.

Animals↗

Cloning of the human and mouse type X collagen genes and mapping of the mouse type X collagen gene to chromosome 10.

Type X collagen, a homotrimer of alpha 1 (X) polypeptide chains, is specifically expressed by hypertrophic chondrocytes in regions of cartilage undergoing endochondral ossification. We have previously described the isolation of a small fragment of the human type X collagen gene (COL10A1) and its localization to the q21-q22 region of human chromosome 6 [Apte, S., Mattei, M.-G. & Olsen, B. R. (1991) FEBS Lett. 282, 393-396]. Using this fragment as a probe to screen genomic libraries, we report here the isolation of human and mouse genomic clones which contain the major part of the human and mouse type X collagen genes. In both species, the 14-kb genomic clones which were isolated contain a long open reading frame (greater than 2000 bp in length) which codes for the entire C-terminal non-collagenous (NC1) domain, the entire collagenous (COL) domain and part of the N-terminal non-collagenous (NC2) domain of the alpha 1(X) collagen chain. The human genomic clone contains the major part of the COL10A1 gene, in addition to the region we have previously cloned, and is highly similar to the corresponding portions of the mouse genomic clone (84.5% similarity at the nucleotide level, and 86.1% at the level of the conceptual translation product). The identification of the mouse genomic clone as the alpha 1(X) collagen gene (Col10a1) was confirmed by in situ hybridization of a fragment of the mouse genomic clone to sections from newborn mice. Hybridization was restricted to the hypertrophic chondrocytes of developing chondroepiphyses, being absent in small chondrocytes and in other tissues. Using interspecific backcross analysis, the locus for the mouse alpha 1 (X) collagen gene was assigned to chromosome 10. The cloning and chromosomal mapping of the human and mouse alpha 1 (X) collagen genes now permit the investigation of the possible role of type X collagen gene defects in the genesis of chondrodysplasias in both species and provide data essential for the generation of transgenic mice deficient in type X collagen.

Amino Acid Sequence↗

Murine common acute lymphoblastic leukemia antigen (CD10 neutral endopeptidase 24.11). Molecular characterization, chromosomal localization, and modeling of the active site.

To further analyze CD10/NEP function in lymphoid and nonlymphoid cells using well characterized murine systems, we isolated the murine CD10/NEP homologue, determined its chromosomal location, and modeled the enzyme's active site. The murine CD10/NEP cDNA predicts a 750-amino acid (aa) type II integral membrane protein with 90% identity to the human CD10 sequence and 100% conservation of critical aa and functional motifs. The latter include the pentapeptide consensus sequence required for zinc binding and catalytic activity, additional aa associated with substrate binding, and the extracellular cysteines that participate in disulfide bonds required for enzymatic activity. Like its human homologue, murine CD10/NEP has multiple alternative 5'-untranslated region sequences. The gene is localized on the proximal half of murine chromosome 3. In Northern analysis, murine CD10/NEP transcripts are abundant in bone marrow stromal cells that support pre-B cell differentiation but are undetectable in representative Abelson transformed pre-B cell lines. The murine CD10/NEP active site was modeled by aligning critical conserved CD10/NEP residues with comparable residues in the active site of thermolysin, a bacterial metalloprotease with similar substrate specificity. The model predicts that the two enzymes have similar clefts that comprise the active site and permit zinc-dependent substrate interactions.

Amino Acid Sequence↗

Primary structure and chromosomal localization of human and mouse rod photoreceptor cGMP-gated cation channel.

We have determined the primary structures of the human and mouse retinal rod cGMP-gated cation channel by analysis of cDNA clones and amplified DNA. The open reading frames predicted polypeptides of 690 and 683 residues exhibiting 88% sequence similarity. Sequence comparison indicated that the rod channels consist of a variable 90-residue N-terminal region, a short highly charged segment rich in lysine and glutamate, and a 540-residue C-terminal portion that is well conserved in three mammalian species. Significant sequence similarity (59%) of the visual cGMP-gated channel to the olfactory cAMP-gated channel established the existence of a family of cyclic nucleotide-gated ion channel genes. RNA blot analysis revealed transcripts of 3.2 kilobases (kb) in human, mouse, and dog, 3.2, 4.6, and 5.2 kb in bovine, and 3.6 kb in fish. The human channel gene was mapped by polymerase chain reaction of somatic cell hybrid DNAs to chromosome 4 (p14-q13) near the centromere. The mouse channel gene locus (Cncg) was mapped by interspecific backcross haplotype analysis 0.9 centimorgan proximal of the Kit locus on chromosome 5.

Amino Acid Sequence↗

Characterization of mouse thrombospondin 2 sequence and expression during cell growth and development.

Thrombospondin (TSP) is an extracellular matrix glycoprotein whose expression has been associated with a variety of cellular processes including growth and embryogenesis. The recent discovery of the existence of a second mouse TSP gene necessitates careful examination of the discrete biochemical and functional properties associated with each molecule. In this report, the primary structures of human TSP, mouse TSP1 (mTSP1), mouse TSP2 (mTSP2), and chicken TSP are compared; and the expression of mTSP1 and mTSP2 during embryogenesis and growth factor-mediated cell proliferation is examined. The cloning and sequencing of the entire coding regions of mTSP1 and mTSP2 revealed considerable conservation of residues critical for TSP structure and function; these data suggest that TSP2 is capable of trimer formation and many of the same cell-surface and ligand interactions that mediate TSP function. Comparison of the various TSP sequences also allowed the assignment based on sequence homology of previously reported human TSP as TSP1 and chicken TSP as TSP2. mTSP2, like mTSP1, was shown to be a primary response gene when quiescent Swiss 3T3 cells were stimulated with serum, platelet-derived growth factor BB, basic fibroblast growth factor, or interleukin-1 beta. Interestingly, TSP1 and TSP2 exhibited markedly different tissue- and stage-specific patterns of mRNA expression during mouse embryogenesis, implying that the two TSP molecules possess discrete functional properties important for development. Additionally, the TSP genes (Thbs1 and Thbs2) were mapped to single loci on mouse chromosomes 2 and 17, respectively.

3T3 Cells↗

A linkage map of mouse chromosome 1 using an interspecific cross segregating for the gld autoimmunity mutation.

An interspecific backcross was used to define a high resolution linkage map of mouse Chromosome (Chr) 1 and to analyze the segregation of the generalized lymphoproliferative disease (gld) mutation. Mice homozygous for gld have multiple features of autoimmune disease. Analysis of up to 428 progeny from the backcross [(C3H/HeJ-gld x Mus spretus)F1 x C3H/HeJ-gld] established a map that spans 77.6 cM and includes 56 markers distributed over 34 ordered genetic loci. The gld mutation was mapped to a less than 1 cM segment on distal mouse Chr 1 using 357 gld phenotype-positive backcross mice. A second backcross, between the laboratory strains C57BL/6J and SWR/J, was examined to compare recombination frequency between selected markers on mouse Chr 1. Significant differences in crossover frequency were demonstrated between the interspecific backcross and the inbred laboratory cross for the entire interval studied. Sex difference in meiotic crossover frequency was also significant in the laboratory mouse cross. Two linkage groups known to be conserved between segments of mouse Chr 1 and the long arm of human Chrs 1 and 2 where further defined and a new conserved linkage group was identified that includes markers of distal mouse Chr 1 and human Chr 1, bands q32 to q42.

Animals↗