ISSN:1424-8581    

DOI:10.1159/000130502

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

An analysis of the pattern of association of acrocentric chromosomes with nonacrocentric chromosomes in human lymphocyte metaphases was performed. This pattern is nonrandom with respect to chromosome length and intrachromosomal distribution. There is a general preference for the centric regions, most pronounced at the proximal segments of the long arms of chromosomes 1, 9, and 16, which is interpreted to reflect heterochromatin attraction during interphase. Comparison of the association patterns of homologous chromosome l’s differing with regard to the size of their heterochromatic regions corroborates this interpretation. The possible significance of heterochromatin attraction for the formation of spontaneous and induced chromosome anomalies is discusse

ISSN:1424-8581    

DOI:10.1159/000130503

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

The mitotic chromosomes of two species of gibbons (Hylobates lar and H. concolor) are examined and compared, using various banding techniques. These two species have very different karyotypes. At the most, seven pairs of chromosomes have a similar banding pattern. The other elements generally differ by complex structural rearrangements. Thus, it is difficult to propose a scheme for chromosomal evolution at this stage. Comparison with the karyotypes of man and anthropoid apes also shows very important differences; very few chromosomes are common or only slightly modified. Some considerations about the hypothetical origin of particular chromosomal structures are given.

ISSN:1424-8581    

DOI:10.1159/000130504

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A karyotype of the gibbon, Hylobates, has been prepared based on the chromosome banding patterns produced by quinacrine, trypsin-Giemsa, and centromeric heterochromatin stains. The banding patterns of H. lar and H. moloch are virtually identical. No brilliant quinacrine-fluorescent areas are present. The banding pattern of most of the gibbon chromosomes show less resemblance to those of the human, chimpanzee, gorilla, or orangutan than the chromosomes of the higher primates do to each other, suggesting a relatively large evolutionary separation of the gibbon from the higher primates. A pericentric inversion of chromosome 7 is present in one gibbon.

ISSN:1424-8581    

DOI:10.1159/000130505

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

A large family is described in which a (21q22q) Robertsonian translocation is segregating through three generations. The assessment of the risk of a translocation carrier producing an offspring with Down’s syndrome is calculated from the data in this family and eight others reported in the literature. The risk when the translocation carrier is a female is approximately 6 in 100, or 0.06. For the male translocation carrier the risk can only be guessed, since the patients with Down’s syndrome born to these parents were probands. The risk for Down’s syndrome from the combined data of male and female translocation carriers is 3 in 100, or

ISSN:1424-8581    

DOI:10.1159/000130506

出版商:S. Karger AG    

年代:1975

数据来源: Karger

摘要:

Ohnuki’s method for demonstrating coils in human metaphase chromosomes also reveals a fine G-band pattern on prophase chromosomes of sufficient clarity to justify an attempt at mapping. Maps are provided for each chromosome to show the maximum number of prophase bands observed, and an intermediate stage in chromosome contraction, tracing the pathways of apparent band fusion as the cell progresses to metaphase, is presented. The prophase bands on many chromosomes tend to occur in distinct groups, the members of which ultimately merge to give the dark G-bands of metaphase chromosomes. Every G-band of the standard metaphase pattern is compounded from two or more prophase bands. In the least contracted prophase chromosomes examined, some bands are seen which have no obvious metaphase counterpart. There are marked similarities between banded prophases and the chromomere pattern seen at meiotic prophase. However, since chromosome contraction is a dynamic process, agreement between maps will be expected only for corresponding degrees of chromosome contractio

ISSN:1424-8581    

DOI:10.1159/000130507

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130508

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130509

出版商:S. Karger AG    

年代:1975

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130510

出版商:S. Karger AG    

年代:1975

数据来源: Karger