ISSN:1424-8581    

DOI:10.1159/000134510

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134511

出版商:S. Karger AG    

年代:1997

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134512

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Thromboxane A2 plays physiological and pathophysiological roles in many tissues. We isolated a cDNA for rat thromboxane synthase from the kidney and here show the location of rat thromboxane synthase gene (Tbxas) on rat chromosome 4q21→q22 by fluorescence in situ hybridization to metaphase chromatin of rat lymphocyte

ISSN:1424-8581    

DOI:10.1159/000134513

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Recently, we reported the isolation of a new subfamily of serine-threonine protein kinases. This subfamily was shown to consist of at least four members. Sequencing and FISH mapping of all 4 members now reveals that the Y-homolog (PRKY) of the previously mapped PRKX gene (Xp22.3) is located in Yp11.2, in close vicinity to AMELY. The other two copies reside on Xq112→q13(PRKXP2) and 15q26(PRKXP1, containing CA repeat STS D15S87) and represent pseudogene

ISSN:1424-8581    

DOI:10.1159/000134514

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

A pooled DNA probe from P1artificial chromosome clones (PACs) containing the human lecithin:cholesterol acyl transferase (LCAT) gene cluster was used in fluorescence in situ hybridization (FISH) experiments assigning the genes to pig chromosome 6p13. In addition, probes derived from the coding regions in the human gene cluster were used in long range mapping experiments to show that the overall structures of the human and porcine LCAT gene clusters are identical. Both the linear order and the close physical distance of five apparently unrelated genes have been maintained throughout 90 million years of divergent evolution between human and pig. The extremely dense clustering of the genes in the LCAT gene cluster suggests that this gene organization has biological significance. The conservation of the gene cluster between human and pig supports this suggestion.

ISSN:1424-8581    

DOI:10.1159/000134515

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

We identified a marker chromosome in the CHO K1 cell line containing amplifications of interstitial telomeric sequences originating from Chinese hamster chromosome 10. Analysis of the progression of this chromosome in two sub-clones of CHO K1 revealed sensitivity of one amplicon to chromosome breakage, resulting in telomere function at the break site. In addition, two more marker chromosomes, both containing amplifications of interstitial telomeric sequences from chromosome 10, were formed during karyotypic evolution of the CHO K1 subclones. The presence of some of the marker chromosomes was also identified in the radiosensitive xrs 5 cell line derived from CHO K1. These results indicate instability of CHO K1 chromosomes containing interstitial telomeric sequences originating from Chinese hamster chromosome 10.

ISSN:1424-8581    

DOI:10.1159/000134516

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

We investigated the effects of treatment of mitotic human fibroblasts with the topoisomerase II inhibitor etoposide (VP-16) on chromosome segregation at anaphase and the genetic consequence to daughter cells of topoisomerase inhibition during mitosis. The most striking effect of VP-16 treatment during mitosis was the production of anaphase cells with several entangled chromosomes (catenated anaphase cells). To analyze the effects of sister chromatid catenation at anaphase on the daughter cells, several interphase methodologies were applied to binucleated human fibroblasts that were blocked during cytokinesis. Post-treatment of mitotic cells with the cytokinesis inhibitor cytochalasin-B maintains the reciprocal products of a mitotic division in the same cytoplasm, allowing the distribution of whole chromosomes or chromosome fragments in daughter nuclei or micronuclei to be followed. The presence of micronuclei containing kinetochores, as detected by antikinetochore staining, suggested that VP-16 treatment during mitosis induces chromosome loss in binucleated fibroblasts. Induction of aneuploid cells for chromosomes 7 and 11 was observed by double in situ hybridization using chromosome-specific alphoid probes in binucleated fibroblasts. In addition, double in situ hybridization with adjacent alphoid and classical satellite DNA probes to chromosome 1 demonstrated that both numerical and structural aberrations contribute to the genetic effects of topoisomerase II inhibition in mitosis.

ISSN:1424-8581    

DOI:10.1159/000134517

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Fluorescence in situ hybridization (FISH) has proven useful for the identification of chromosomal material of unknown origin. More recently, comparative genomic hybridization (CGH) has been used to identify deletions and amplifications, particularly in neoplastic samples. Here, we describe the combined use of CGH and FISH to identify the origin of a de novo unbalanced translocation in a newborn with multiple congenital anomalies. GTG banding of metaphases from cultured lymphocytes showed an unbalanced karyotype, with extra material on a chromosome 5: 46, XX, add(5)(q35). Parental karyotypes were both normal. CGH revealed the additional material was from distal 1 1q (11q23→qter). This finding was confirmed by FISH with a whole chromosome paint for chromosome 11. Based on the CGH and FISH analyses, the pro-band’s karyotype was therefore 46, XX, der(5)t(5;11)(q35.2; q23.2).ish der(5)(wcp11+). This case demonstrates the efficient use of CGH and confirmatory FISH for the identification of chromosomal material of unknown ori

ISSN:1424-8581    

DOI:10.1159/000134518

出版商:S. Karger AG    

年代:1997

数据来源: Karger

摘要:

Human chromosomes 1, 2, 3, and 11 were tagged with pSV2 neo and transferred via microcell fusion from mouse A9 human monochromosomal hybrids to a chicken pre-B cell line, DT40, proficient for homologous recombination. Hybrids containing two copies of human chromosome 11 were transfected with targeting vectors containing a mammalian selectable gene with either the Dl 1S16 or HRAS genomic sequences corresponding to two different chromosome 11 loci. Analysis of stable transfectants showed a high frequency (∼80%) of targeted integration of these constructs into each of the homologous loci of human chromosome 11 in DT40 hybrids. The results suggest that any human genomic sequences on human chromosomes transferred into DT40 cells could be targeted at high frequency, thereby allowing for subsequent modification of human genes and chromosome

ISSN:1424-8581    

DOI:10.1159/000134519

出版商:S. Karger AG    

年代:1997

数据来源: Karger