摘要:

Human chromosome preparations were subjected to a wide range of treatments — heat, enzymatic digestion, acid, and alkali. These treatments included the conditions of a standard Giemsa-banding procedure, a trypsin-banding method, and the reverse-banding procedure of Dutrillaux and Lejeune (1971). The slides were then stained with acridine orange, which fluoresces green in combination with double-stranded, and red with single-stranded, nucleic acids. Under various conditions, including those of the three banding procedures mentioned, chromosome banding was obtained with acridine orange. The pattern was always the same and resembled “reverse” banding, with bright yellow/green fluorescence in the regions of R-bands. Quinacrine and standard Giemsa-bands corresponded to dull red/orange staining with acridine orange. The results are interpreted as suggesting that chromosome banding patterns correspond to regions whose DNA differs in the ease with which it denatures and the extent to which it reanneals. These properties could be related to variation in associated chromosomal pro

ISSN:1424-8581    

DOI:10.1159/000130450

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

The termination sequences of DNA replication, as visualized in tritiated-thymidine autoradiographs of chromosomes of Carollia perspicillata, appear to follow this order: euchromatin → G-bands → C-bands → facultative heterochro

ISSN:1424-8581    

DOI:10.1159/000130451

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

A quantitative analysis of Colcemid-induced chromosomal nondisjunction in cultured Chinese hamster cells is presented. Chromosome counts were made immediately following nondisjunction and also determined for colonies arising after treatment. Nondisjunction of a single chromosome occurred randomly. When two or more chromosomes were involved, the process was nonrandom and appeared to be independent of chromosome size. The frequency distribution of the extra chromosomes in single and multiple trisomic clones which survived Colcemid treatment was nonrandom, although every group could be involved. Monosomy appeared in 0.8 % of the surviving clones. Although monosomy for each chromosome grouping was observed immediately after nondisjunction, only monosomics involving the smaller chromosomes proliferated beyond this stage to form a colony.

ISSN:1424-8581    

DOI:10.1159/000130452

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Cytogenetic studies were performed in 1969, 1970, and 1971 on the Yanomama and Piaroa Indians of Venezuela. The early studies involved 49 Yanomama, of whom 13 had 23 cells with extensive chromosome breakage and rearrangement, so-called complex cells. The virtual disappearance of these complex cells in subsequent studies of the Yanomama was accompanied by a decline in the percentage of cells with any aberration, from 4.2 in 1969, to 2.6 in 1970, to 1.4 in 1971. This progressive decrease in abnormalities may bethe result of the elimination of chromosomally damaged cells after exposure to a chromosome-breaking agent.

ISSN:1424-8581    

DOI:10.1159/000130453

出版商:S. Karger AG    

年代:1973

数据来源: Karger

摘要:

Evidence based on analysis of mouse-human somatic-cell hybrids is presented that supports the assignment for the structural loci of peptidase A to human chromosome 18 and of cytoplasmic glutamate oxaloacetate transaminase (GOT) (EC 2.6.1.1) to chromosome 10. The medical and evolutionary significance of these assignments is discussed.

ISSN:1424-8581    

DOI:10.1159/000130454

出版商:S. Karger AG    

年代:1973

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130455

出版商:S. Karger AG    

年代:1973

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130456

出版商:S. Karger AG    

年代:1973

数据来源: Karger