摘要:

The banding automatic system (BAS) we describe in this paper is a computer-assisted karyotyping system suitable for the analysis of both normal and abnormal karyotypes in banded chromosome specimens. In the BAS system recognition of the various features and constituents of the chromosomes is performed by an operator, whereas chromosome identification and classification are entrusted to a computer. The connection between operator and computer is the CYGENl program, which is tailored to distinguish chromosome morphology on the basis of the operator input band patterns alone. The karyotyping operation is therefore significantly speeded up: the operator simply has to read through a certain number of banded metaphases, encoding band-pattern data to the computer. The machine signals when the operation has gone through the whole karyotype or, for instance, when chromosomes are missing or present in extra number above the significance level from the analyzed metaphases. Chromosome identification and classification are then carried out by the computer, which performs as a real-time recognizing key. Moreover, the data being accumulated in the computer will provide a file of cytogenetic records accessible to the operator, as well as to the computer, for further diagnostic operations. The efficacy of the BAS system is demonstrated for the diagnosis of various structural aberrations, including a complex translocation. The processing of 20 metaphases by the method described takes 40–45 min, and a cytogenetic technician can make effective use of the system after 25–30 h of intensive train

ISSN:1424-8581    

DOI:10.1159/000131545

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Freeze-induced injury is a commonly observed phenomenon with cultured fibroblasts from patients with I-cell disease (ICD). Cells from these patients have therefore not been widely available to investigators, which has inhibited the study of this complex disorder. Skin biopsies from three ICD patients, as well as fibroblast cultures derived from these biopsies, have been subjected to a series of freezing experiments. The results show that when standard freezing protocols are employed, skin biopsies from these patients, in contrast to cultured fibroblasts, tolerate freezing well. In addition, when subjected to prolonged incubation in the confluent state, fibroblast cultures will consistently withstand frozen storage and, upon thawing, will yield actively growing cultures, biochemically and morphologically indistinguishable from the cultures that were frozen. There was a direct correlation between incubation time at confluence and subsequent cell survival after freezing.

ISSN:1424-8581    

DOI:10.1159/000131546

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Cells of the V79–4 Chinese hamster line were found to have a consistent set of 20 chromosomes. G- and C-band analysis showed that, compared to the standard 22 chromosome set of freshly isolated Chinese hamster cells, the V79–4 chromosomes had various characteristic deletions and rearrangements. However, it is probable that at least one copy of each autosome was still present, and three pairs of autosomes appeared unchanged from those in the freshly isolated cells. The establishment of this karyotype for V79–4 allows mutant sublines to be screened for chromosomal changes associated with the altered phenotype, and an example is given of a radiation-induced mutant lacking HPRT activity that had a clear X-chromosome rearrang

ISSN:1424-8581    

DOI:10.1159/000131547

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

Bovine embryonic trachea cells were hybridized with mouse A9 cells deficient in hypoxanthine phosphoribosyltransferase, and cattle-mouse hybrid cell clones were isolated after HAT/ouabain selection. In these interspecific cell hybrids, bovine glucose-6-phosphate dehydrogenase, α-galactosidase, and phosphoglycerate kinase were expressed concordantly with bovine HPRT. Their expression depended on the presence of the bovine X chromosome. These data indicate that the genes for G6PD, PGK, and HPRT are linked and can be assigned to the bovine X chromosome

ISSN:1424-8581    

DOI:10.1159/000131548

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

A sequence derived by ECoRI restriction of human satellite DNA III has been cloned in λgt WES. The cloned DNA was used as a template for in vitro synthesis of cRNA, which was hybridized in situ to preparations of human metaphase chromosomes with a range of heterochromatic polymorphisms. Most of the hybridization was found on chromosome 1, and the amount of hybridization was related to the size of the C-band on this chromosome. Hybridization to other chromosomes was not related to the C-band size, although hybridization of total satellite DNA is proportional to C-band size. Total satellite DNAs contain a mixture of sequences, some of which are predominantly located on only one pair of chromosomes. Hybridization in situ is able to discriminate between such chromosome-specific sequences and the bulk of satellite DNA. Further analysis of satellite DNAs may identify sequences specific for every chromosome pair

ISSN:1424-8581    

DOI:10.1159/000131549

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The patterns of late replication of human fetal lung fibroblasts and renal epithelium in culture were compared using a terminal pulse of 3H-TdR or of BrdU followed by autoradiography or Hoechst and Giemsa staining, respectively. Fifty cells from each of two fetuses were scored with each technique. Statistically significant quantitative differences were found in the pattern of late replication of the two tissues, but these differences were not consistent between the two individuals. In cultures from both of the fetuses examined, the autoradiographic grain counts over a given segment of chromosomes 1, 4, and 5 in the two tissues were shown to differ by a factor of 2 or more, while with BrdU chromosomes 1, 2, 4, and 13 had a labeling frequency that differed by 20% or more over a given band. The results suggest that although there are tissue-specific differences in the patterns of late replication, these differences do not reflect changes in the state of differentiation.

ISSN:1424-8581    

DOI:10.1159/000131550

出版商:S. Karger AG    

年代:1981

数据来源: Karger

摘要:

The patterns of late replication were compared on direct chromosome preparations from cells of chick embryo lung and kidney, as well as in cultures established from these tissues using tritium autoradiography. Fifty cells from each tissue were examined from each of five animals in vivo and three in vitro. Two- to four-fold differences in the frequencies with which a chromosome arm labeled were seen when lung and kidney were compared; however, labeling differences were often equally significant in the opposite direction when cells from another chick embryo were analyzed. The results obtained in vivo were comparable to those seen in vitro, indicating that cell-culture did not alter cell differentiation in a way that could be detected by late replication patterns. Variation in tissue-specific differences in late replication between individuals suggests that these patterns do not reflect differences in the differentiated state.

ISSN:1424-8581    

DOI:10.1159/000131551

出版商:S. Karger AG    

年代:1981

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000131552

出版商:S. Karger AG    

年代:1981

数据来源: Karger