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J Forejt

Publications and source records attributed to J Forejt.

At least 37 records · Page 2Linked to original sources
PubMed1996

A novel type of retinoic acid response element in the second intron of the mouse H2Kb gene is activated by the RAR/RXR heterodimer.

We have identified and characterized a novel retinoic acid (RA) response element (Hi-RARE) in the second intron of the mouse major histocompatibility H2Kb gene. The Hi-RARE sequence is conserved in all mouse classical and Q class 1 genes, in MHC class 1 genes of the rat, Rhesus macaque, cat and in the vast majority of human classical and non-classical class 1 genes. The Hi-RARE sequence lies within a regulatory element responsible for constitutive expression of a 5' enhancerless H2Kb gene in the Ltk-fibroblasts. Hi-RARE consists of two inverted palindromic RARE consensus sites (5'-PuGGTCA-3') separated by an 8 nt spacer. Mutational analysis revealed that both inverted palindromic hexanucleotide motifs are indispensable functional sites for the 9-cis RA response. The Hi-RARE sequence confers 9-cis RA inducibility to a heterologous promoter. The inducibility is further augmented in embryonal carcinoma cells by the expression of recombinant retinoic acid receptors (PARs) and the retinoid X receptors (RXRs). In vitro, the recombinant RAR/RXR heterodimer creates DNA-protein complex with the Hi-RARE sequence. Treatment of P19 embryonal carcinoma cells with 9C-RA induces the Hi-RARE binding activity of nuclear proteins that proved to be RAR (or RAR-Like)/RXR heterodimer. Thus the Hi-RARE represents a new type of RA response element with a role in the modulation of the expression of MHC class 1 family genes.

Animals↗
PubMed1996

Sub-milliMorgan map of the proximal part of mouse Chromosome 17 including the hybrid sterility 1 gene.

We have generated a high-resolution genetic map, 0.071 cM per backcross animal, of the 13 cM T-H2 region of the mouse Chromosome (Chr) 17. The map contains two phenotypic loci, T and Hst1, 12 RFLP markers, and 24 microsatellite loci. The Hst1 gene was mapped to a chromosomal interval contained within a single 580-kb YAC clone. The FFEH11 YAC is 0.44 cM long and carries, besides the Hst1 gene, five polymorphic DNA markers and recombination breakpoints of six backcross animals. Two candidate genes for Hst1 were identified based on their location and testicular expression. These are Tbp and D17Ph4e. The submilliMorgan map of the T-H2 region revealed significant clustering of (CA)n loci. The clustering, if shown to be a common feature in the mouse genome, may cause gaps in the physical map of the mouse genome.

Animals↗
PubMed1996

Hybrid sterility in the mouse.

The sterility of hybrids between various mouse species follows Haldane's rule by affecting only the males. Hitherto, five hybrid sterility (Hst) loci have been identified in the mouse genome. Haldane's rule holds also for chromosomal sterility in all studied mammalian species, including man. The males heterozygous for various male-sterile chromosomal rearrangements show the same meiotic phenotype: partially asynaptic, rearranged autosomes associate with the X Chromosome. Thus, the X-Chromosome inactivation in the male meiosis might function as a checkpoint leading to the meiotic arrest in sterile hybrids. Chromosomal and gene hybrid sterility might be interrelated because the attributes of chromosomal sterility, such as X-autosome associations, occur also in interspecies hybrids with genic sterility.

Animals↗
PubMed1996

Use of continuous blood volume monitoring to detect inadequately high dry weight.

A continuous blood volume monitoring (CBVM) device (Inline Diagnostics, Riverdale, USA) was used to study response to prescribed ultrafiltration during haemodialysis (HD) in 66 stabilised HD patients. Fifty percent of patients showed the expected linear decrease in BV right from the beginning of HD (group 1), 32% exhibited no decrease at all (group 2), while eighteen percent formed the transient group 3 which showed a plateau of varying length after which a decrease occurred. The correct setting of dry weight was verified through evaluation of the ratio of extracellular fluid volume to total body water (VEC/TBW) in 26 patients by means of whole body multifrequency impedometry MFI (Xitron Tech., San Diego, USA) and through measurement of the Vena Cava Inferior diameter (VCID) pre and post HD (in 6 and 5 patients from groups 1 and 3 and from group 2, respectively). The mean VEC/TBW in groups 1 and 3 was 0.56 pre and 0.51 post HD as compared to 0.583 and 0.551 in group 2. VCID decreased on average by 14.1% in groups 1 and 3 but remained stable in group 2. Both findings thus confirmed inadequately high estimation of dry weight. Since CBVM is extremely easy to perform it can be used as a method of choice in detecting inadequately high prescribed dry weight. The status of the cardiovascular system must always be considered before final judgement is made.

Blood Volume↗
PubMed1995

[Determination of dry weight of hemodialyzed patients on the basis of the ratio of extracellular fluid volume to total body fluid volume as measured by multifrequency impedance].

Whole body impedometry is relatively new non-invasive method to measure the distribution of total body water (TBW) between extra- and intracellular compartment (VEC, VIC). Having applied linear regression analysis onto the relation of the ratio of the extracellular volume to the volume of total body water (VEC/TBW) and the age in a group of healthy individuals very narrow scatter from the regression line was found. This line can thus be used as an indicator of normohydration status with respect to age. Assuming that the relation of VEC/TBW vs. age is the same in dialysed patients and that the state of normohydration corresponds to the so called dry weight, the VEC/TBW value can be used as a novel indicator of dry weight. Any deviation of the pre-dialysis VEC/TBW value from normal could easily be used to establish the desired ultrafiltration and dry weight. With regard to the known inaccuracy with which the dry weight is determined from purely clinical assessment this approach may lead to substantial objectivisation in determination of this principal parameter. It may be especially helpful in case of newly admitted patients. The suggested new approach to dry weight determination is supported by the finding of statistically significant relation between post-dialysis deviation of the VEC/TBW ratio from the normal value vs. blood volume reduction at the end of the dialysis session. Patients classified at the end of a dialysis session as still overhydrated by their VEC/TBW deviation from normal showed little or no reduction in their blood volume. An investigation of the Vena Cava Inferior diameter in a subgroup of these patients confirmed this finding showing no decrease at the end of dialysis. On the contrary, the patients whose post-dialysis VEC/TBW value was normal or below normal showed both significant reduction in their blood volume as well as decrease in the Vena Cava Inferior diameter.

Adult↗
PubMed1994

Physical map of mouse chromosome 17 in the region relevant for positional cloning of the Hybrid sterility 1 gene.

Hybrid sterility 1 (Hst1) is the major gene responsible for sterility of male hybrids between Mus musculus and certain laboratory strains. Thus, Hst1 is of importance in studying both postreproductive isolation of closely related species and male fertility. It has been mapped to mouse chromosome 17 in the region corresponding to the third inversion of the t haplotypes. The aim of the present study was to construct a physical map of the Hst1 region as the first step in an effort to clone the gene. Three yeast artificial chromosome (YAC) libraries (Princeton, Whitehead, and ICRF) were screened with polymerase chain reaction (PCR) oligonucleotide primers and DNA probes specific for loci previously mapped into the region of the third inversion. The isolated YAC clones were restriction mapped and arranged into contigs. Sixteen YAC clones were arranged into a single contig encompassing a region approximately 2000 kb long based on restriction mapping of highly overlapping but independently derived YAC clones. Five new loci in the region of the third inversion were mapped and the order and approximate physical distances of 12 loci established in this contig. The Hst1 gene maps approximately 0.2 cM proximal to the D17Ph1 locus encompassed by the YAC contig. Since the contig extends at least 1200 kb proximal to D17Ph1, it should contain the Hst1 gene.

Animals↗
PubMed1992

Genetic analysis of genomic imprinting: an Imprintor-1 gene controls inactivation of the paternal copy of the mouse Tme locus.

The Thp deletion on mouse chromosome 17 is lethal when inherited from the mother, because it deletes the T-associated maternal effect (Tme) locus, the paternal copy of which is inactivated by genomic imprinting. We have found a paternally nonimprinted Tme variant in crosses of Thp females with Mus m. musculus males. The data are consistent with the existence of a single Tme-unlinked gene, Imprintor-1 (Imp-1), with two alleles, one of which only causes imprinting at the Tme locus. Imp-1 is unlinked to the gene for cation-dependent Man-6-P receptor and acts prezygotically. Although Tme and Igf2r were thought to be identical, they show different patterns of imprinting in interspecies hybrids. The apparent nonequivalence of the Igf2r gene and Tme results in occurrence of viable mice lacking an active Igf2r gene. These mice are bigger at birth than their normal littermates, in accord with the proposed function of the IGF-II/Man-6-P receptor.

Animals↗
PubMed1992

A novel downstream regulatory element of the mouse H-2Kb class I major histocompatibility gene.

The H-2Kb gene equipped with a minimal promoter (5' deletion up to -61) was fully expressed in transfected fibroblasts, but inactive in transfected embryonal carcinoma cells. A strong transcriptional regulatory element (H2DRE) was identified when a fragment spanning the second exon and second intron was used to activate transient expression of the reporter chloramphenicol acetyltransferase (CAT) gene in mouse Ltk- or NIH3T3 fibroblasts. Its activity was twice that of a construct where the CAT gene was driven by the H-2Kb 5' enhancer region (H2TF1/KBF1 site) and comparable to that of pRSVCAT construct carrying the strong Rous sarcoma virus LTR enhancer. In accord with regulated transcriptional activity of the intact H-2Kb gene, the H2DRE did not activate the CAT expression in P19 mouse embryonal carcinoma cells. The H2DRE did not function as a typical enhancer since its activity was strongly position dependent. Consistent with its anticipated role in transcription regulation, H2DRE displayed more than five target sites for specifically interacting nuclear factors, two of them being present in H-2 positive fibroblasts, but not in H-2 negative teratocarcinoma cells. None of them was cross-competed by sequences of the 5' enhancer. The results of deletion experiments show that H2DRE is the only regulatory region that can activate transcription from the 5' enhancerless H-2Kb gene in mouse L fibroblasts.

Animals↗
PubMed1991

Genetic mapping of the t-complex region on mouse chromosome 17 including the Hybrid sterility-1 gene.

t-haplotypes occupy a region on chromosome (Chr) 17 which slightly overlaps the ends of the T-H-2 interval. The wild-type form of this 14 centi-Morgan (cM) region was mapped in a multilocus backcross (C57BL/10-T x C3H)F1 x C57BL/10 using 15 DNA probes on Southern blots of the DNA extracted from 53 animals which were recombinants in the T-H-2 interval. Each recombinant was also progeny-tested to ascertain its Hybrid sterility-1 (Hst-1) genotype by crossing to PWB/Ph, a Mus musculus-derived inbred strain. The limit of resolution of the cross was 0.27 cM. The map distances have been determined for the DNA loci in the T-H-2 interval and the Hst-1 gene was mapped in close vicinity to the D17Rp17 locus.

Animals↗
PubMed1990

Differences in the organization and chromosomal allocation of satellite DNA between the European long tailed house mice Mus domesticus and Mus musculus.

We compared the organization of satellite DNA (stDNA) and its chromosomal allocation in Mus domesticus and in Mus musculus. The two stDNAs show similar restriction fragment profiles after digestion (probed with M. domesticus stDNA) with some endonucleases of which restriction sequences are present in the 230-240 bp repetitive unit of the M. domesticus stDNA. In contrast, EcoRI digestion reveals that M. musculus stDNA lacks most of the GAATTC restriction sites, particularly at the level of the half-monomer. The chromosome distribution of stDNA (revealed by an M. domesticus stDNA probe) shows different patterns in the M. domesticus and M. musculus karyotypes, with about 60% of M. domesticus stDNA retained in the M. musculus genome. It is particularly noteworthy that the pericentromeric regions of M. musculus chromosomes 1 and X are totally devoid of M. domesticus stDNA sequences. In both groups, the differences in energy transfer between the stDNA-bound fluorochromes Hoechst 33258 and propidium iodide suggest that AT-rich repeated sequences have a much more clustered array in the M. domesticus stDNA, as if they are organized in tandem repeats longer than those of M. musculus. Considering the data as a whole, it seems likely that the evolutionary paths of the two stDNAs diverged after the generation of the ancestral 230-240 bp stDNA repetitive unit through the amplification, in the M. domesticus genome, of a family repeat which included the EcoRI GAATTC restriction sequence.

Animals↗
PubMed1989

Linkage map of mouse chromosome 17: localization of 27 new DNA markers.

Chromosome 17 of the laboratory variant of the house mouse (Mus musculus L.), MMU17, has been studied extensively, largely because of its involvement in the control of immune response and embryonic as well as male germ cell differentiation. A detailed linkage map of this chromosome is therefore a highly desired goal. As the first step toward achieving this goal, we have isolated, using a LINE 1 repetitive sequence as a probe, 52 anonymous DNA clones from MMU17. Twenty-seven repetitive sequence-free probes isolated from these clones displayed restriction fragment length variation among common inbred strains and could be mapped with the help of recombinant inbred strains, congenic strains, F2 segregants, or intra-t recombinants. Together with markers identified previously, the new markers can be used to construct a map of MMU17 that contains 125 DNA loci. The markers are distributed over a length of approximately 71 cM, which probably represents the entire length of MMU17. Most of the markers reside in the proximal portion of the chromosome, which contains the t and H-2 complexes; this chromosomal region is now fairly well mapped. The distal region of MMU17, on the other hand, is populated by only a few, rather imprecisely mapped markers. Molecular maps are available for most of the H-2 complex and for parts of the t complex.

Animals↗
PubMed1988

Allelic profile at 37 biochemical loci of two inbred strains of the house mouse derived from wild Mus musculus musculus.

Two newly established inbred strains derived from Mus musculus musculus, designated PWD/Ph (F29) and PWK/Ph (F33), were examined for their alleles at 37 biochemical loci located on 12 different chromosomes. The allelic pattern showed characteristic differences from those observed in common inbred strains. The genetic distance D between PWK/Ph and PWD/Ph was 0.027, whereas the corresponding values for the genetic distances between PWK/Ph and C57BL/6J, DBA/2J, BALB/cJ and SWR/J were 0.777, 0.721, 0.721 and 0.838 respectively. New allozymes are described as being controlled by the loci Es-23, Pre-2 and Tam-1. The genetic relationship to M.m.molossinus is indicated by identical alleles at six other loci (Es-2, Es-9, Es-10, Es-11, Es-18 and Es-22).

Alleles↗