ISSN:1424-8581    

DOI:10.1159/000132725

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

We describe a family in whom the phenotypically normal father carries a balanced insertional translocation, ins(14;11)(q23;p12p14). This individual fathered three mentally retarded children, two with a del(11)(p13) and one with a dup(11)(p13). Two other cases of a de novo del(11)(p13) are also described. All four del(11)(pl3) cases presented with WAGR, a complex syndrome associated with a predisposition to Wilms’ tumor (WT), aniridia (A), genitourinary abnormalities (G), and mental retardation (R). Using an approach combining karyotype analysis, determination of the gene copy number, and RFLP studies employing five 11p13 DNA markers, we were able to define the chromosomal rearrangement involved in each case. Analysis of these WAGR deletions provides further subdivision of band p13 on chromosome 1

ISSN:1424-8581    

DOI:10.1159/000132726

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Previous studies of human triploidy have implicated the autosomes in the regulation of activity of X-linked genes. To determine if the influence of the extra autosomal set in triploids was attributable to a specific autosomal gene, we examined the pattern of DNA replication in females trisomic for 18 of the possible 22 autosomal trisomies. We find no evidence that a single gene or chromosome in triplicate can effect X-chromosome replication or activity. Our results suggest either that more than one locus in triplicate is required to maintain the activity of two X chromosomes, or that the influence of the extra autosomal set in enabling the activity of more than a single X chromosome is mediated indirectly, perhaps through the agency of increased nuclear size or changes in the cell cycle.

ISSN:1424-8581    

DOI:10.1159/000132727

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Over 500 probes revealing restriction fragment length polymorphisms (RFLPs) have been isolated by Schumm et al. (1988). We describe here the chromosomal assignment of 14 of the most highly polymorphic markers in that set of probes, with polymorphism information content values of up to 0.98. The probes were mapped using a panel of human × rodent somatic cell hybrids and were found to be distributed among nine different autosomes. Chromosome localization of such highly polymorphic markers has been an important step in the construction of the human genetic map, as a large number of RFLP probes has now been localized by genetic linkage studies to these loci

ISSN:1424-8581    

DOI:10.1159/000132728

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Tumor cells from 70% of neuroblastoma patients contain a deletion of part of the short arm of chromosome 1, indicating that this chromosomal region includes a gene involved in tumor formation. To more precisely evaluate the boundaries and mechanisms involved in generating these deletions, we have examined four neuroblastoma cell lines using a combination of somatic cell hybridization, isozyme analysis, and nucleic acid hybridization employing both standard and restriction fragment length polymorphic probes. The data suggest that the truncation of chromosome 1 in these neuroblastomas was most likely due to a complex translocation and deletion mechanism rather than a simple unbalanced translocation or terminal or interstitial deletion. This conclusion is supported by the frequent removal of MYCL from the altered chromosome 1 to another chromosome. Furthermore, the data suggest that the frequency of breakpoints previously assigned by karyotypic analysis to bands other than lp32 in neuroblastomas may be overestimated. Finally, this study identified a breakpoint at 1p32 that was localized between the genes JUN and MYCL for one neuroblastoma thus establishing the order of these genes as centromere, JUN, MYCL, telomere. We conclude that the observed breakpoints within chromosome 1p in human neuroblastoma are not as variable as previously described and suggest the results of this study provide evidence for the involvement of specific DNA sequences within lp32 in the generation of neuroblastoma.

ISSN:1424-8581    

DOI:10.1159/000132729

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Parathymosin is a 101-amino acid polypeptide involved in the regulation of cellular immunity. In situ hybridization of rat parathymosin cDNA to human metaphase chromosomes localized the gene for human parathymosin to the q12→q22 region of chromosome 1

ISSN:1424-8581    

DOI:10.1159/000132730

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Use of prometaphase chromosome preparations has led to significant improvements in the localization of both NORs and ribosomal gene clusters in the short arms of human acrocentric chromosomes. An improvement of the NOR silver-staining method, followed by trypsin-Giemsa banding, was used to identify the precise location of the NOR on each human acrocentric chromosome. For comparison, the satellite, stalk, and centromeric region were also identified with the aid of both Q- and G-banding techniques. The amount of silver impregnation present in the stalk region of the D- and G-group chromosomes was unique for each of these acrocentric chromosomes and depended on the length of the stalk. In situ hybridization was used to locate the ribosomal gene clusters. A plasmid containing 5.6 kb of the 18S rDNA gene was first oligolabeled with bio-16-dUTP, then hybridized in situ to metaphase chromosomes and visualized by an alkaline phospha-tase color-detection system. Our results indicated that, in most cases, the location of the 18S rDNA gene cluster in the stalk region was indistinguishable from the site of silver impregnation. However, exceptions were noted, suggesting a multiplicity of arrangements of the ribosomal gene clusters. A model is proposed to describe the spatial relationship of NORs (transcriptional activity) and the ribosomal gene clusters.

ISSN:1424-8581    

DOI:10.1159/000132731

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Diandric triploid mouse embryos were produced by standard micromanipulatory techniques, using eggs isolated from female mice with a normal chromosome constitution that had been mated to homozygous Rb(1.3)lBnr males (which carry a large metacentric “marker” chromosome, viz., a Robertsonian translocation involving chromosomes 1 and 3). The tripronucleate embryos were transferred to the oviducts of pseudopregnant mice, which were subsequently autopsied at about midday on the 10th day of gestation. Although a relatively small number of the isolated conceptuses consisted of morphologically abnormal egg-cylinder-like structures or empty gestational sacs, most were at clearly distinguishable embryonic stages, from the primitive streak stage to embryos with about 20 pairs of somites present. These embryos all appeared to be morphologically normal but were substantially smaller than normal (diploid) fertilized embryos analyzed at similar stages of development. A total of 63 diandric triploid conceptuses were recovered and analyzed cytogenetically. They were G-banded to determine their sex-chromosome constitution and confirm their diandric triploid status. No obvious difference was observed in the developmental potential of the 58, XXX class of diandric triploids, compared to that of the 58, XXY class. The ratio of 58, XXX to 58, XXY embryos was close to the expected ratio of 1:2, assuming that unfertilized eggs have an equal chance of becoming fertilized by an X- or a Y-bearing spermatozoon and that the additional (i.e., “donor”) male pronucleus also has an equal chance of having either an X or a Y sex chromosome present. However, the development of the 58, XYY class appeared to be restricted, even at the stage of gestation analyzed, in that no embryos with this genetic constitution were observed that had progressed beyond the early somite stage. The present findings are discussed in relation to the cytogenetic findings in human triploid conceptuses, the majority of which are spontaneously aborted during the first half of pregnancy. In man, the 69, XYY class (equivalent to the 58, XYY class in our study) is only rarely encountered, and it has been assumed that these triploid embryos are probably lost at a very early stage of ge

ISSN:1424-8581    

DOI:10.1159/000132732

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Usher syndrome is an autosomal recessive disease characterized by dual sensory impairments; affected individuals are born with a sensorineural hearing loss and ultimately lose their sight as retinitis pigmentosa develops. Conventional protein markers previously tested in a Louisiana Acadian kindred suggested tentative linkage to vitamin D-binding protein on chromosome 4. DNA linkage studies do not confirm this linkage relationship and exclude much of chromosome 4 as the site of the Usher syndrome gene in these families.

ISSN:1424-8581    

DOI:10.1159/000132733

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The cytokines, IL-3, IL-4, IL-5, and GM-CSF (encoded by murine genes Il-3, Il-4, Il-5, and Csfgm) belong to a family of secreted glycoprotein hormones that regulate the haemopoietic and immune systems. We demonstrate here using in situ hybridization that Il-3 and Il-5 are both probably located in the segment comprising band A5 and the proximal half of band B1 on mouse chromosome 11 with a possible location point in band B1 near its proximal interface with band A5. In studies reported elsewhere we have shown close physical linkage between Il-3 and Csfgm and also between Il-4 and Il-5. The in situ hybridization results therefore indicate that all four cytokine genes are clustered on chromosome 11 raising the possibility that they arose by ancient gene duplication.

ISSN:1424-8581    

DOI:10.1159/000132734

出版商:S. Karger AG    

年代:1989

数据来源: Karger