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D J Gilbert

Publications and source records attributed to D J Gilbert.

At least 199 records · Page 11Linked to original sources
PubMed1995

Genomic structure, promoter identification, and chromosomal mapping of a mouse nuclear orphan receptor expressed in embryos and adult testes.

We have isolated and characterized overlapping genomic clones containing the complete transcribed region of a newly isolated mouse cDNA encoding an orphan receptor expressed specifically in midgestation embryos and adult testis. This gene spans a distance of more than 50 kb and is organized into 13 exons. The transcription initiation site is located at the 158th nucleotide upstream from the translation initiation codon. All the exon/intron junction sequences follow the GT/AG rule. Based upon Northern blot analysis and the size of the transcribed region of the gene, its transcript was determined to be approximately 2.5 kb. Within approximately 500 bp upstream from the transcription initiation site, several immune response regulatory elements were identified but no TATA box was located. This gene was mapped to the distal region of mouse chromosome 10 and its locus has been designated Tr2-11. Immunohistochemical studies show that the Tr2-11 protein is present mainly in advanced germ cell populations of mature testes and that Tr2-11 gene expression is dramatically decreased in vitamin A-depleted animals.

Amino Acid Sequence↗
PubMed1995

The mouse APLP2 gene. Chromosomal localization and promoter characterization.

Senile plaques are primarily comprised of deposits of the beta-amyloid precursor-like proteins APLP1 and APLP2. proteins (APPs). APP is a member of a gene family, including amyloid precursor-like proteins APLP1 and APLP2. Using interspecific mouse backcross mapping, we localized the mouse APLP2 gene to the promixmal region of mouse chromosome 9, syntenic with a region of human 11q. We cloned an approximately 1.2-kilobase mouse genomic fragment containing the APLP2 gene promoter. The APLP2 promoter lacks a typical TATA box, is GC-rich, and contains several sequences for transcription factor binding. S1 nuclease protection analysis revealed the presence of multiple transcription start sites. The lack of a TATA box, the presence of a high GC content, and multiple transcription start sites place the APLP2 promoter in the class of promoters of "housekeeping genes." Regulatory regions within the promoter were assayed by transfection of mouse N2a and Ltk- cells with constructs containing progressive 5'-deletions of the APLP2 promoter fused to the bacterial chloramphenicol acetyl transferase (CAT) reporter gene. A minimal region that includes sequences 99 bp upstream of the predominant transcription start site of the APLP2 promoter was sufficient to direct high levels of CAT expression.

Alzheimer Disease↗
PubMed1995

Molecular cloning, expression, chromosomal assignment, and tissue-specific expression of a murine alpha-(1,3)-fucosyltransferase locus corresponding to the human ELAM-1 ligand fucosyl transferase.

Terminal Fuc alpha 1-3GlcNAc moieties are displayed by mammalian cell surface glycoconjugates in a tissue-specific manner. These oligosaccharides participate in selectin-dependent leukocyte adhesion and have been implicated in adhesive events during murine embryogenesis. Other functions for these molecules remain to be defined, as do the tissue-specific expression patterns of the corresponding alpha-(1-3)-fucosyltransferase (alpha 1-3FT) genes. This report characterizes a murine alpha 1-3FT that shares 77% amino acid sequence identity with human ELAM ligand fucosyltransferase (ELFT, also termed Fuc-TIV). The corresponding gene maps to mouse chromosome 9 in a region of homology with the Fuc-TIV locus on human chromosome 11q. In vitro, the murine alpha 1-3FT can efficiently fucosylate the trisaccharide Gal alpha 1-3Gal beta 1-4GlcNAc (apparent Km of 0.71 mM) to form an unusual tetrasaccharide (Gal alpha 1-3Gal beta 1-4[Fuc alpha 1-3]GlcNAc) described in periimplantation mouse tissues. The enzyme can also form the Lewis x determinant from Gal beta 1-4GlcNAc (Km = 2.05 mM), and the sialyl Lewis x determinant from NeuNAc alpha 2-3Gal beta 1-4GlcNAc (Km = 1.78mM). However, it does not yield sialyl Lewis x determinants when expressed in a mammalian cell line that maintains sialyl Lewis x precursors. Transcripts from this gene accumulate to low levels in hematopoietic organs, but are unexpectedly abundant in epithelia that line the stomach, small intestine, colon, and epididymus. Epithelial cell-specific expression of this gene suggests function(s) in addition to, and distinct from, its proposed role in selectin ligand synthesis.

Amino Acid Sequence↗
PubMed1995

Assignment of the beta B1 crystallin gene (CRYBB1) to human chromosome 22 and mouse chromosome 5.

By using primers complementary to the rat beta B1 crystallin gene sequence, we amplified exons 5 and 6 of the orthologous human gene (CRYBB1). The amplified human segments displayed greater than 88% sequence homology to the corresponding rat and bovine sequences. CRYBB1 was assigned to the group 5 region in 22q11.2-q12.1 by hybridizing the exon 6 PCR product to somatic cell hybrids containing defined portions of human chromosome 22. The exon 5 and exon 6 PCR products of CRYBB1 were used to localize, by interspecific backcross mapping, the mouse gene (Crybb1) to the central portion of chromosome 5. Three other beta crystallin genes (beta B2(-1), beta B3, and beta A4) have previously been mapped to the same regions in human and mouse. We demonstrate that the beta B1 and beta A4 crystallin genes are very closely linked in the two species. These assignments complete the mapping and identification of the human and mouse homologues of the major beta crystallins genes that are expressed in the bovine lens.

Animals↗
PubMed1995

Chromosomal localisation, inducibility, tissue-specific expression and strain differences in three murine peroxisome-proliferator-activated-receptor genes.

Three murine peroxisome-proliferator-activated-receptor (PPAR) genes were localised to chromosome 15 (PPAR alpha), chromosome 17 (PPAR beta) and chromosome 6 (PPAR gamma). The expression of the three PPAR RNAs was determined using a specific RNase protection assay. In liver RNA, PPAR alpha was expressed at the highest level, with 20-fold lower levels of PPAR beta, and very low levels of PPAR gamma. The three PPAR RNAs showed no sex-specific differences in expression, and the levels of these transcripts were unaffected by treatment of mice with testosterone or the potent peroxisome proliferator, methylclofenapate. In agreement with this data, the level of PPAR alpha protein in liver was unchanged after treatment of mice with methylclofenapate. Investigation of the tissue-specific distribution revealed that the PPAR alpha RNA was expressed at highest levels in liver, to moderate levels in kidney and brown adipose tissue, and at low levels elsewhere. PPAR beta was expressed at moderate levels in liver, and lower levels in other tissues, including brown adipose tissue. In contrast, PPAR gamma RNA was expressed at low levels in liver or epididymal white adipose tissue and at very low levels elsewhere, but was expressed at high levels in brown adipose tissue. The tissue distribution of these receptors suggests an important role in lipid metabolism and toxicity for individual members of the PPAR family. The expression of PPAR alpha and PPAR beta RNAs was examined in 13 strains of mice, and the levels of expression varied within a fourfold range. Polymorphism in the size of PPAR alpha RNA from Swiss-Webster mice was detected, and shown to be due to a 2-bp mutation in the 3' non-coding region of PPAR alpha in Swiss Webster mice.

Adipose Tissue, Brown↗
PubMed1995

Distribution of the mammalian Stat gene family in mouse chromosomes.

Studies of transcriptional activation by interferons and a variety of cytokines have led to the identification of a family of proteins that serve as signal transducers and activators of transcription, Stats. Here, we report that the seven mouse Stat loci map in three clusters, with each cluster located on a different mouse autosome. The data suggest that the family has arisen via a tandem duplication of the ancestral locus, followed by dispersion of the linked loci to different mouse chromosomes.

Animals↗
PubMed1995

Isolation, characterization, and chromosomal localization of mouse and human COUP-TF I and II genes.

Chicken ovalbumin upstream promoter transcription factors (COUP-TFs) are orphan members of the steroid/thyroid hormone receptor superfamily. COUP-TF homologues have been cloned in many species, from Drosophila to human. The protein sequences of COUP-TFs are highly homologous across species, suggesting functional conservation. Two COUP-TF genes have been cloned from human, and their genomic organizations have been characterized. To determine whether the genomic organization is conserved between human and mouse, we isolated two mouse COUP-TF genes (I and II) and characterized their genomic structures. Both genes have relatively simple structures that are similar to those of their human counterparts. In addition, we mapped mouse COUP-TF I to the distal region of chromosome 13 and COUP-TF II to the central region of chromosome 7. Furthermore, we mapped human COUP-TF I to 5q14 of chromosome 5 and COUP-TF II to 15q26 of chromosome 15. The results demonstrate that COUP-TF genes are located in chromosomal regions that are syntenic between mouse and human.

Animals↗
PubMed1995

A novel chemokine, macrophage inflammatory protein-related protein-2, inhibits colony formation of bone marrow myeloid progenitors.

A new member of the beta-chemokine family, macrophage inflammatory protein (MIP)-related protein-2 (MRP-2) was isolated from a murine macrophage cell line, RAW 264.7. MRP-2 is composed of 122 amino acids of which the first 21 residues constitute a putative signal sequence. The putative mature protein is composed of 101 amino acids with a molecular weight of 11,600. MRP-2 is structurally similar to MIP-related protein-1 (MRP-1) (C10) and MIP-1 alpha. MRP-2 shows a 50.8% sequence identity at the protein level to MRP-1 and 46.3% identity to MIP-1 alpha. MRP-2 detects approximately 1.3 kilobase mRNA from monocyte and macrophage cell lines but does not detect the mRNA from T and B cells. The MRP-2 gene termed Scya9 was mapped to the central region of mouse chromosome 11 near the Scya1 and Scya2 genes, which are also members of the beta-chemokine superfamily. The Scya gene cluster was located between neurofibromatosis type 1 (Nf1) and myeloperoxidase (Mpo). rMRP-2 significantly suppressed colony formation by murine and human bone marrow granulocyte-macrophage (CFU-granulocyte-macrophage), erythroid (burst-forming unit-E), and multipotential (CFU-granulocyte-erythroid-macrophage-megakaryocyte) progenitor cells stimulated by combinations of growth factors.

Amino Acid Sequence↗
PubMed1995

Identification of the human beta A2 crystallin gene (CRYBA2): localization of the gene on human chromosome 2 and of the homologous gene on mouse chromosome 1.

By using primers synthesized on the basis of the bovine beta A2 crystallin gene sequence, we amplified exons 5 and 6 of the human gene (CRYBA2). CRYBA2 was assigned to human chromosome 2 by concordance analysis in human x rodent somatic cell hybrids using the amplified PCR products as probe. Regional localization to 2q34-q36 was established by hybridizing the CRYBA2 probe to microcell and radiation hybrids containing defined fragments of chromosome 2 as the only human contribution. The CRYBA2 probe was also used to localize, by interspecific backcross mapping, the mouse gene (Cryba2) to the central portion of chromosome 1 in a region of known human chromosome 2 homology. Finally, we demonstrate that in both species the beta A2 crystallin gene is linked but separable from the gamma A crystallin gene. The beta A2 crystallin gene is a candidate gene for human and mouse hereditary cataract.

Animals↗
PubMed1995

Murine chromosomal location of five bHLH-Zip transcription factor genes.

The genes for the bHLH-Zip transcription factors Tfap4, Mxi1, Tcfeb, Usf1, and Usf2 have been mapped in mouse by interspecific backcross analysis. Mxi1, Usf1, and Usf2 have been mapped previously by in situ hybridization, but their positions on the meiotic linkage map had not been determined. The other two genes have not previously been mapped in mouse. These transcription factors belong to a growing family of transcriptional regulators, some of which are known to form a complex network of interacting proteins that control cell proliferation and apoptosis. As expected, based on mapping studies of other bHLH-Zip genes, these loci were well distributed among mouse chromosomes. In addition, some of the probes used in this study detected multiple, independently segregating loci, suggesting the possible existence of additional family members or species-specific pseudogenes.

Animals↗
PubMed1995

Mouse chromosomal location of the CCAAT/enhancer binding proteins C/EBP beta (Cebpb), C/EBP delta (Cebpd), and CRP1 (Cebpe).

There are four known members of the C/EBP family of basic region-leucine zipper transcription factors: Cebpa, Cebpb, Cebpd, and Cebpe. Cebpa has previously been mapped to mouse chromosome 7. Here, we show that Cebpb maps to mouse chromosome 2, Cebpd to chromosome 16, and Cebpe to chromosome 14. The assignment of Cebpd to chromosome 16 identifies a new region of homology between mouse chromosome 16 and human chromosome 8.

Animals↗
PubMed1995

Cloning, expression, and chromosomal location of SHH and IHH: two human homologues of the Drosophila segment polarity gene hedgehog.

The hedgehog genes encode signaling molecules that play a role in regulating embryonic morphogenesis. We have cloned and sequenced human cDNA copies of two of these genes, SHH and IHH. The SHH clone includes the full coding sequence and encodes a protein 92.4% identical to its murine homologue. The IHH clone is 89% complete and encodes a protein 94.6% identical to its murine homologue. IHH is expressed in adult kidney and liver. SHH expression was not detected in adult tissues examined; however, it is expressed in fetal intestine, liver, lung, and kidney. SHH mapped to chromosome 7q and IHH to chromosome 2 by PCR with DNA from a panel of rodent-human somatic cell hybrids. To identify the chromosomal location of SHH more precisely, a P1 genomic clone of SHH was isolated. This phage contained a CA repeat sequence tagged site that was used to map SHH relative to a polysyndactyly disease locus, using DNA prepared from affected and unaffected members of a large pedigree. SHH is closely linked, but distinct from the polysyndactyly disease locus at 7q36 (maximum lod score = 4.82, theta = 0.05) tightly linked to the EN2 locus. The murine homologues Shh, Ihh, and Dhh were mapped using (C57BL/6J x Mus spretus)F1 x C57BL/6J interspecific backcross. Shh mapped to a position 0.6 cM distal to En2 and 1.9 cM proximal to Il6 on mouse chromosome 5. This location is closely linked but distinct from the murine limb mutation Hx and syntenic to human chromosome 7q36.

Amino Acid Sequence↗
PubMed1995

Mouse chromosomal location of three EGF receptor ligands: amphiregulin (Areg), betacellulin (Btc), and heparin-binding EGF (Hegfl).

The products of five distinct loci, Egf, Tgfa, Areg, Btc, and Hegfl act as ligands for the epidermal growth factor receptor. Egf and Tgfa have previously been mapped to mouse chromosomes 3 and 6, respectively, but the mouse chromosomal locations of Areg, Btc, and Hegfl have not been reported. Here, we show that Areg and Btc are tightly linked on mouse chromosome 5, while Hegfl maps to mouse chromosome 18. We also provide evidence that a putative sixth family member, Sdgf, is in fact a species variant of Areg. These results confirm and extend known relationships between mouse and human chromosomes, and they also provide new information regarding the evolution of this important gene family.

Amphiregulin↗
PubMed1995

A novel cytokine-inducible gene CIS encodes an SH2-containing protein that binds to tyrosine-phosphorylated interleukin 3 and erythropoietin receptors.

Cytokines manifest their function through alteration of gene expression. However, target genes for signals from cytokine receptors are largely unknown. We therefore searched for immediate-early cytokine-responsive genes and isolated a novel gene, CIS (cytokine inducible SH2-containing protein) which is induced in hematopoietic cells by a subset of cytokines including interleukin 2 (IL2), IL3, granulocyte-macrophage colony-stimulating factor (GM-CSF) and erythropoietin (EPO), but not by stem cell factor, granulocyte colony-stimulating factor and IL6. The CIS message encodes a polypeptide of 257 amino acids that contains an SH2 domain of 96 amino acids in the middle. To clarify the function of CIS in cytokine signal transduction, we expressed CIS in IL3-dependent hematopoietic cell lines under the control of a steroid-inducible promoter. The CIS product stably associated with the tyrosine-phosphorylated beta chain of the IL3 receptor as well as the tyrosine-phosphorylated EPO receptor. Forced expression of CIS by steroid reduced the growth rate of these transformants, suggesting a negative role of CIS in signal transduction. CIS induction requires the membrane-proximal region of the cytoplasmic domain of the EPO receptor as well as that of the common beta chain of the IL3, IL5 and GM-CSF receptor, whereas CIS binds to the receptor that is tyrosine phosphorylated by cytokine stimulation. Thus CIS appears to be a unique regulatory molecule for cytokine signal transduction.

Amino Acid Sequence↗
PubMed1995

Structural characterization and chromosomal location of the mouse macrophage migration inhibitory factor gene and pseudogenes.

Macrophage migration inhibitory factor, MIF, is a cytokine released by T-lymphocytes, macrophages, and the pituitary gland that serves to integrate peripheral and central inflammatory responses. Ubiquitous expression and developmental regulation suggest that MIF may have additional roles outside of the immune system. Here we report the structure and chromosomal location of the mouse Mif gene and the partial characterization of five Mif pseudogenes. The mouse Mif gene spans less than 0.7 kb of chromosomal DNA and is composed of three exons. A comparison between the mouse and the human genes shows a similar gene structure and common regulatory elements in both promoter regions. The mouse Mif gene maps to the middle region of chromosome 10, between Bcr and S100b, which have been mapped to human chromosomes 22q11 and 21q22.3, respectively. The entire sequence of two pseudogenes demonstrates the absence of introns, the presence of the 5' untranslated region of the cDNA, a 3' poly(A) tail, and the lack of sequence similarity with untranscribed regions of the gene. The five pseudogenes are highly homologous to the cDNA, but contain a variable number of mutations that would produce mutated or truncated MIF-like proteins. Phylogenetic analyses of MIF genes and pseudogenes indicate several independent genetic events that can account for multiple genomic integrations. Three of the Mif pseudogenes were also mapped by interspecific backcross to chromosomes 1, 9, and 17. These results suggest that Mif pseudogenes originated by retrotransposition.

Amino Acid Sequence↗
PubMed1995

Genomic structure and chromosomal localization of the mouse LIM/homeobox gene Lhx3.

We have previously cloned the murine Lhx3 cDNA that encodes a predicted protein containing two tandemly repeated LIM domains and a homeodomain. Early expression of Lhx3 in oral ectoderm that is committed to contribute to the anterior and intermediate lobes of the pituitary and its perseverance in the adult gland strongly suggest an involvement of the gene in mediating and maintaining the differentiation program of this important endocrine system. Additional functions are suggested by the fact that Lhx3 is also expressed bilaterally along the spinal cord and the hindbrain at early stages of mouse development. Here we report the structural organization and chromosomal localization of the Lhx3 gene. The gene is composed of six exons and five introns. Two different exons, Ia and Ib, appear to be alternatively spliced to exon II. The first LIM domain is encoded by exon II and the second by exon III. The homeobox is shared by exons IV and V. We have mapped Lhx3 to the proximal region of mouse chromosome 2 in a region that shares homology with human chromosomes 9q and 10p.

Amino Acid Sequence↗