摘要:

Fragments of the spacer region of genes for rat 5S ribosomal RNA (rDNA), which are tandemly repeated, were amplified by PCR with primers specific to the two ends of the coding region for 5S rRNA. Two amplified fragments of ∼1.6 kb were subcloned and sequenced. The spacer sequences showed a high degree of sequence identity to each other (99.2%) but substantial divergence from those of analogous mouse clones. The homologous regions in the mouse clones were interrupted by the duplication or deletion of small segments of DNA. A 12-mer, 5-GGCTCTTGGGGC-3’, thought to be responsible for efficient transcription, was located from position -33 to position -22 in the rat 5S clones. The genes were mapped by fluorescence in situ hybridization with cloned fragments of rat 5S rDNA as probe. The genes were localized exclusively in a single telomeric region of chromosome

ISSN:1424-8581    

DOI:10.1159/000134149

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

In this paper, we describe labeling and hybridization conditions for oligonucleotide probes that detect human triplet repeat sequences in yeast artificial chromosomes (YACs). Restriction digests of YACs containing the CAG repeat sequence of the SCA1 gene were used as positive controls. Several hybridization mixtures and temperatures and two different labeling techniques were tested in order to determine optimal conditions. CAG, CGG, AGG, and ATT repeat sequences were mapped on YACs from a contig in 6p23, where SCA1 is located.

ISSN:1424-8581    

DOI:10.1159/000134150

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The chromosomal localization of the gene for retinoblastoma (RBI), which has been mapped to band 13q14 in man, was studied by in situ hybridization on metaphase chromosomes of selected primates, including Pithecia pithecia, Macaca sylvana, and Cercopithecus aethiops tantalus. The results allowed us to determine the position of the bands homologous to human chromosome band 13ql4 in these species. Hybridization analysis corroborated the results of previous studies that defined the chromosome homologous to human chromosome 13 (HSA 13) in these species. By comparing RB1 localizations and banding patterns, it is shown that the rearrangement separating HSA 13 from its homologous chromosome in Cercopithecidae is not a pericentric inversion, as suggested by earlier studies. Since the banding pattern and RB 1 localization are not changed, the modification of the centromeric index is explained by a centromeric shift or by two inversions, one pericentric and one paracentric.

ISSN:1424-8581    

DOI:10.1159/000134151

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Somatic cell hybrids were obtained by cell fusions between Lck-positive EL4 mouse T lymphoma cells and Lck-negative B82 mouse fibroblasts or S194 mouse plasmacytoma cells to examine negative control of lck gene expression in the resulting hybrids. Western blot analysis using a monoclonal antibody against the Lck protein showed a marked decrease in p56lck expression in B82 × EL4 (BEL) hybrids. In contrast to BEL hybrids, the level of p56lck was not changed significantly in S194 × EL4 (SEL) hybrids and was approximately one-half of that seen in EL4 cells. Diminished expression of the Lck protein in BEL hybrids paralleled downregulation of lck mRNA, which was exclusively transcribed from the distal promoter in EL4 cells. It is unlikely that the suppression was simply a consequence of chromosome segregation critical for lck gene expression, since BEL hybrids retained the EL4-derived lck gene and most of the chromosomes from both parental cells. The results from treatment of BEL hybrids with actinomycin D or cycloheximide suggested that suppression of lck gene expression in the hybrids might not be due to posttranscriptional control. DNA methylation status in the lck distal promoter and the coding regions did not appear to correlate with the expression of the gene. Our results suggest that negative control of lck gene expression differs between fibroblasts and B cells, in that lck gene expression in T cells can be shut down by transfer of a putative repressor factor or factors in fibroblasts but not in B cell

ISSN:1424-8581    

DOI:10.1159/000134152

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant peripheral neuropathy characterized by recurrent episodes of nerve palsies. We have analyzed 11 microsatellite markers from chromosome 17p12→p11 in nine French families with HNPP. The three microsatellites D17S839 (afm200yb12), D17S955 (afm317yg1), and D17S921 (afm91xh12) were localized in the deleted region. In allele segregation analyses, the microsatellite D17S793 (afm165zd4) detected two chromosome 17-linked loci, one of which was deleted in HNPP patients. Using these STR markers, we found that the deletion coincided with the CMT1A/HNPP monomer unit in eight of the nine families. In the remaining pedigree, the deletion lay between the centromeric microsatellite D17S805 (afm234tal) and the telomeric marker D17S922 (afm197xh6), which flank the CMTIA monomer unit. Comparison of these data with the available genetic and physical maps of 17p12→p11 shows that this region, which is frequently subject to rearrangement-inducing diseases, such as Smith-Magenis syndrome, Charcot-Marie-Tooth type 1A, and HNPP, presents recombination hot spots. Finally, this study demonstrates the usefulness of the D17S122 (RM11GT) and D17S921 (afm191xh12) microsatellites as tools for the molecular diagnosis of H

ISSN:1424-8581    

DOI:10.1159/000134153

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

G- and C- banding patterns of seven species of the bat family Molossidae, Eumops glaucinus, E. perotis, Molossops abrasus, M. temminckii, Molossus ater, M. molossus, and Nyctinomops laticaudatus, were identified. Comparisons among the karyotypes of these species showed extensive homologies between E. perotis, M. ater, M. molossus, M. abrasus, and N. laticaudatus, demonstrating inter- and intrageneric conservatism, and a lesser degree of homologies in M. temminckii and E. glaucinus, reflecting intrageneric variation. Chromosomal variation was due to inversions, Robertsonian rearrangements, translocations, and variations in the location of constitutive heterochromatin and nucleolus organizer regions. The chromosome corresponding to No. 5 in the M. ater karyotype is discussed. We suggest that the Nyctinomops and Molossops karyotypes represent the primitive condition and that Molossus and Eumops have derived karyotypes.

ISSN:1424-8581    

DOI:10.1159/000134154

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The co-utilization of FISH and PRINS techniques for in situ chromosome screening was tested on human sperm nuclei. We used a centromeric repeat probe specific for chromosome 4 for FISH. PRINS reactions were performed with α-satellite primers specific for either chromosome 9 or chromosome 18. Double labeling was obtained and estimates of disomy rates were carried out for the three chromosomes

ISSN:1424-8581    

DOI:10.1159/000134155

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Superoxide dismutase 1 (SOD1) was mapped to cattle chromosome 1q12→q14 by in situ methods. Both traditional in situ hybridization using tritium and a new technique, direct in-situ single copy PCR (DISC-PCR), were used in two separate laboratories. Both human and bovine SOD1 clones were tritium labeled for radioactive in situ hybridization. A primer pair based on the bovine SOD1 gene (Barendse et al., 1994b) was used for the DISC-PCR procedure. The map location of SOD1 is close to collagen 6A1. SOD1 is a potentially important type 1 anchor locus in the region where the gene for horns in cattle was recently mapped (Georges et al., 1993; Schmutz et al., 1995

ISSN:1424-8581    

DOI:10.1159/000134156

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

The human endogenous retrovirus K10 (HERV-K10) was mapped to human chromosomes using HERV-K10 specific PCR primers on a somatic hybrid mapping panel. A non-random chromosomal location was demonstrated with PCR signals on chromosomes 1, 3, 4, 5, 6, 7, 10, 11, 12, 14 ,15, 19, 20, 21 22 and Y. There was a lack of PCR products on the other chromosomes, even after hybridization with a HERV-K10 specific probe. To further localize the HERV-K10 sequence we used fluorescence in situ hybridization. Chromosomes 1, 3, 6, 7, 10, 11, 12 and 22 were found to contain several HERV-K10 sequences in different regions. The presence of several integration sites on some chromosomes is consistent with previous studies demonstrating 30–50 copies of the HERV-K10 sequence per haploid genome. The mapping information reported in this study will assist the analysis of the biological significance of the HERV-K10 sequenc

ISSN:1424-8581    

DOI:10.1159/000134157

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

A young female carrier for incontinentia pigmenti underwent preimplantation genetic diagnosis to prevent the transfer of affected embryos. FISH diagnosis was performed using X, Y, 18 and 13/21 probes. Unexpectedly, 57% of the embryos were aneuploid for these chromosomes, a rate significantly higher (P < 0.005) than expected (9.3%). The patient achieved pregnancy but spontaneously aborted a trisomy 9 fetus.

ISSN:1424-8581    

DOI:10.1159/000134158

出版商:S. Karger AG    

年代:1996

数据来源: Karger