摘要:

Chromosome microdissection arose as a means of facilitating long range physical mapping of chromosome regions involved in either a genetic or malignant disorder. However, with the rapid development of improved techniques for mapping and sequencing the human genome, microdissection is considered by many investigators to be a cumbersome and time consuming procedure. Nonetheless, based on the impressive number of informative diagnostic DNA markers that are now available as a result of this technology, microdissection still must be considered one of the most rapid and direct methods available for generating new DNA markers from any chromosome region, irrespective of its sequence composition. In addition, it remains an important means to dissect DNA markers from any organism, eukaryotic and prokaryotic, and has resulted in generating disease associated DNA sequences from both human and animal genomes. Recently, microdissection of single cells has emerged as a viable alternative for isolating pure populations of specific cell types, especially tumor cells, which can then be studied without background contamination from any other cellular constituents. This overview will provide a glimpse into the present applications of the microdissection technology, as well as the importance this technology will have for future exploration into the human genome.

ISSN:1424-8581    

DOI:10.1159/000134407

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134408

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134409

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134410

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134411

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Centromere protein C (CENP-C), a human centromere autoantigen, is a component of the inner kinetochore plate. CENP-C is required for maintaining proper kinetochore size and a timely transition to anaphase. In this study using fluorescence in situ hybridization to metaphase chromosomes, the human CENP-C gene (CENPC) was mapped on chromosome 4, region q13→q2

ISSN:1424-8581    

DOI:10.1159/000134412

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

A sperm chromosome analysis of 24 men with normal or balanced karyotypes was carried out to study the frequency of sperm chromosome aneuploidy. A total of 3,446 human sperm complements (36–315 per donor) was analyzed after in vitro penetration of hamster eggs. Two sets of donors were studied at two different centers in the United States (center 1) and Spain (center 2). The frequencies of hyperhaploidy and hypohaploidy in control donors were similar between center 1 (1.9% vs. 7.7%) and center 2 (1.8% vs. 10.3%). In carrier donors there were no significant differences between the two centers in the frequency of hyperhaploidy (0.8 % vs. 1.9 %), but that of hypohaploidy was significantly higher in center 2 (11.0%) than in center 1 (4.6%). A significant excess of hypohaploid complements, as compared to hyperhaploid complements, was found in both centers in both control and carrier donors. The sex ratio was similar in both centers and did not differ significantly from a 1:1 sex ratio. The larger chromosomes in the complement (1, 2, 3, 4, 5, 7, and 10) presented a significantly lower frequency of hypohaploidy, while some of the smaller chromosomes (13, 19, and 21) showed a higher frequency of hypohaploidy than expected. Chromosome 21 and the sex chromosomes showed an increase in the percentage of hyperhaploidy, as compared to other chromosomes, that was close to statistical significance (P = 0.08). Our results reflect a preferential loss of small chromosomes during slide preparation and suggest that chromosome 21 and the sex chromosomes could be more frequently involved in aneuploid

ISSN:1424-8581    

DOI:10.1159/000134413

出版商:S. Karger AG    

年代:1996

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000134414

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Cytogenetic studies were performed on three species of eyelidless microteiids, Procellosaurinus erythrocerus, P. tetradactylus, and Vanzosaura rubricauda (Squamata, Gymnophthalmidae), all with a diploid number of 2n = 40. The specimens were collected in the palaeoquartenary dune fields of the middle Rio São Francisco in the State of Bahia, Brazil. Chromosomes from fibroblast cultures were studied after routine Giemsa staining, CBG- and RBG-banding, and Ag-NOR staining. Despite similarities in chromosome number and morphology, each species can be differentiated by the position and amount of C-heterochromatin. Our cytogenetic and DNA content data indicate that there are more similarities between the two species of Procellosaurinus than exist between either species and V. rubricauda, reinforcing the importance of banding techniques for the characterization of reptilian species

ISSN:1424-8581    

DOI:10.1159/000134415

出版商:S. Karger AG    

年代:1996

数据来源: Karger

摘要:

Here we report a high-resolution fluorescence in situ hybridization (FISH) analysis of the integrated Epstein-Barr virus (EBV) genome in chromosomes, decondensed interphase nuclear chromatin, and linearly extended chromatin fibers. We analyzed the EBV DNA integrated into the human genome in the well-characterized Burkitt’s lymphoma cell line Namalwa, which contains two complete EBV genomes. The integration occurs via the terminal repeats of the virus and was always detectable at chromosome band lp35. Using the biotinylated Bam HIW fragment of the viral DNA, we observed distinct pairs of signals or small nuclear RNA “tracks” within interphase nuclei. FISH to stretched DNA fibers has a higher resolving power and, therefore, enables analysis of the structural organization of DNA. Application of this methodology to linearly extended chromatin of Namalwa cells using different EBV fragments allowed us to visualize the ordered arrangement of the integrated virus. Based on the predicted span of 0.34 nm per base pair for relaxed DNA, length measurements of 30 images showed a good correlation between the mean physical length of hybridized EBV DNA of 52.8 µm (158 kb) without the terminal repeats, and the EBV genomic length of 172 kb, including the terminal repeats. This DNA mapping procedure represents a useful tool for studying the structural organization of integrated viral genomes, and its application will have implications for the understanding of integration pro

ISSN:1424-8581    

DOI:10.1159/000134416

出版商:S. Karger AG    

年代:1996

数据来源: Karger