摘要:

By culturing heparinized whole blood, satisfactory chromosome preparations have been obtained easily and efficiently from blood samples as small as 0.05 ml. This technique eliminates any special treatment of the blood prior to initiating culture and minimizes the loss of leukocytes from the sample. It is particularly useful in those situations where separation of the leukocytes from other blood cells is difficult. Chromosomes from humans and deer mice have been studied using this technique.

ISSN:1424-8581    

DOI:10.1159/000129767

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Studies were made of the somatic chromosome constitutions of a group of 14 mongoloids, including two who were sibs, together with the available members of their immediate families. In eight cases the classical trisomy for chromosome 21 was the only abnormality observed. The mongoloid sibs fell into this category. In the remaining six cases, however, some other abnormality was also observed in the mongoloid family. The abnormalities seen include an unusually long Y chromosome, an unusually long small acrocentric, an abnormal chromosome 18, and translocations or deletions in some portion of the karyotypes. The high frequency of abnormal chromosomes in these families suggests that these “minor” abnormalities may increase the frequency of nondisjunction of other chromosomes during meiosis, thus increasing the probability of mongoloid offspring in these famil

ISSN:1424-8581    

DOI:10.1159/000129768

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Chromosome abnormality associated with the clinical syndrome of mongolism can usually be attributed to primary non-disjunction during gametogenesis. Nevertheless, a variety of chromosome abnormalities not attributable to primary non-disjunction during gametogenesis have been described, usually in mongols born to young mothers. The authors of this paper report a 48/46 chromosome mosaicism in a mongol born to a young mother. The cell line with 48 chromosomes has five chromosomes of the 21–22 group (Denver system) and a centric fragment. The cell line with 46 chromosomes has an extra chromosome with the morphology of the 19–20 group and only three chromosomes of the 21–22 group. It is suggested that this mosaicism resulted from concurrent non-disjunction of a number 21 and transverse division of the centromere of a second number 21 during early cleavage in a zygote, or cell line, with 47 chromosomes and trisomic for chromosome numb

ISSN:1424-8581    

DOI:10.1159/000129769

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Blood grouping of a pair of twin sisters rendered it probable that they are monozygotic twins. One was severely mentally retarded and had a number of signs of Turner’s syndrome. This twin later died. Autopsy revealed normal ovaries. The other twin is phenotypically normal. In both twins XO/XX sex chromosome mosaicism was demonstrate

ISSN:1424-8581    

DOI:10.1159/000129770

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

A boy now aged two years has a number of congenital defects, including mental deficiency, cerebral atrophy, spastic tetraplegia, low-set, malformed ears, dental abnormalities and malformations of the extremities. Chromosome studies have revealed a modal number of 47, the extra chromosome being a very small metacentric chromosome. The karyotypes of the parents and of a brother showed nothing abnormal.

ISSN:1424-8581    

DOI:10.1159/000129771

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Human peripheral leukocyte cultures 66 hours old have been irradiated with X rays and fixed 6 hours later. The cells were scored for chromosomal aberrations. The aberrations seen were mainly of the chromatid type, and included all of the expected types. The average coefficient of breakage production for four experiments was 0.0031, or virtually the same as that found earlier (Bender and Gooch, 1962a) for chromosome-type aberrations induced in the human leukocyte system.

ISSN:1424-8581    

DOI:10.1159/000129772

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Cultured human cells from 3 females and 1 male were studied both in the living state in phase contrast and after fixation and Feulgen or thionin staining. A dense particle, the size of sex chromatin, is found lying adjacent to the nuclear membrane in 46% of living female cells. This particle is identical with the sex chromatin seen in the same cells after Feulgen or thionin staining. In 10% of living female cells the sex chromatin is very faint but becomes dense and distinct after fixation. In about 30% of female cells sex chromatin cannot be seen in the living state but can be clearly identified after fixation and Feulgen staining. In 10% of female nuclei no sex chromatin at all is found in Feulgen-stained preparations. A particle similar to sex chromatin is found only very rarely in living male cells. The fine structure of sex chromatin suggests that it consists of a folded thread, ½–1 µmthick and 3–5 µm long.It is concluded that the density or state of condensation of the sex chromatin is not the same in all nuclei in a particular culture at one time. No marked changes in structure and density of the sex chromatin occurred during the observation on single cells for periods up to 52 hours, except in one case, where a sex chromatin appeared in the hitherto homogeneous nucleus shortly before pr

ISSN:1424-8581    

DOI:10.1159/000129773

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

In the family described here, the grandmother, father, and 3 of his 9 children had an apparently abnormal chromosome of group 21–22. The abnormality was similar in morphology in all the affected subjects and was found in metaphases from cultures of leukocytes, and skin and bone marrow. The short arm of the abnormal chromosome seemed longer than normal; it was not possible to ascertain whether the satellite itself or the short arm, or both, were enlarged. Of the 5 subjects affected, 4 were clinically normal. The fifth, a girl, had severe abnormalities of the central nervous system. One of her brothers, who was cytogenetically normal, had a similar syndrome of unknown origin. From these data, and from those published by others, it was postulated that an apparently enlarged satellite region is compatible with normal development. Such an abnormality does not necessarily imply an association with developmental disorder in the offspring of carrier subject

ISSN:1424-8581    

DOI:10.1159/000129774

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Chromosome counts and karyotype data are presented for five primates Tupaiaglis (Common tree shrew) has 62 chromosomes, 12 metacentric and 48 acrocentric autosomes, a metacentric X and acrocentric Y. Nycticehus coucang (Slow loris) has 5·chromosomes all of which including the X and Y, are metacentric. Tarsius bancanus (Horsfield’s tarsier) has 80 chromosomes, the highest number recorded for any mammal, 14 are metacentric and 66 are acrocentric. Since only a female could be studied the sex chromosomes were not identified. Cercocebus aterrimus (Black mangabey) has 42 chromosomes of which all, including the X and Y, are metacentric. Symphalangus syndactylus (Siamang) has 50 chromosomes of which 48, including the X and Y are metacentric and 2 are acrocentric. The karyotype of this species is compared with that of Hylobates lar (White-handed gibbon). These findings support the trend observed by others that within an order species with high chromosome numbers have many acrocentrics and those with low numbers have more metacentrics. This suggests that structural rearrangements may have played a large role in evolution. Whether more “specialized” forms have primarily acrocentric chromosomes and “generalized” forms less is discussed. It is concluded that more data is required to verify both of these

ISSN:1424-8581    

DOI:10.1159/000129775

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Two collections of XY-containing karyotypes were screened to obtain every karyotype in which the Y chromosome was distinguishable from the other small acrocentric chromosomes. The metaphase figures corresponding to these karyotypes were then examined, and approximately one-fourth of these were discarded because of marked distortion of the chromosome spread. The 37 remaining metaphase figures, 22 from the Columbia-Presbyterian collection and 15 from the Southbury collection were used to study the frequency of peripheral location of specific chromosomes. Five circular metaphase figures from each collection were selected for measurement of the distance of specific chromosomes from the center. In each collection the five metaphase figures were of similar area, but the Southbury metaphase figures were approximately 25 per cent larger in area than the Columbia-Presbyterian metaphase figures. All metaphase figures were obtained by flattening cells from human leucocytes cultures that had been treated with colchicine and hypotonic sodium citrate prior to fixation.

ISSN:1424-8581    

DOI:10.1159/000129776

出版商:S. Karger AG    

年代:1963

数据来源: Karger