摘要:

Autoradiographic studies of human chromosomes labeled with tritiated thymidine have been carried out on cells from 15 individuals with normal and abnormal karyotypes. The labeling method that was applied is based on the observation that, in the late part of the DNA synthetic period (S-period), specific, large chromosome segments complete DNA replication at different time intervals. The DNA replication patterns are reported as they were observed, for individual chromosome pairs, during the last two hours of the S-period. It is demonstrated that the method has become a useful tool for chromosome identification and characterization, and a detailed description of the techniques used, is given. Secondary constrictions in certain chromosome pairs which have been demonstrated by means of special techniques (Sasaki and Makino, 1963; Saksela and Moorhead, 1962) are shown to coincide with specific, late DNA replicating chromosome regions.

ISSN:1424-8581    

DOI:10.1159/000129778

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

A family showing transmission of a D/D type translocation is reported. The chromosomes involved are probably Nos. 13 and 15 (Denver). Attempts to localize a number of marker genes in relation to the centromere of the translocated chromosome were unsuccessful. The propositus in this family was a case of regular (21-trisomy) Down’s syndrome (Mongolism). The possible association between non-disjunction and the translocation is discussed both in relation to the present family and others in the literatur

ISSN:1424-8581    

DOI:10.1159/000129779

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

A 21-month-old boy with multiple congenital anomalies was found to have 49 chromosomes with an XXXXY sex chromosome constitution. He was mentally retarded with skeletal abnormalities, hypertelorism, malformed and asymmetrical ears, a short broad neck and small external genitalia. A testicular biopsy specimen showed defective germ cell and tubule development. Autoradiographic studies with tritiated thymidine showed asynchrony in DNA synthesis of the chromosomes of cultured skin and testis cells. In cells labelled late during the DNA synthetic period three heavily labelled X chromosomes were demonstrated. Autoradiographs of interphase nuclei derived from the same cultures showed localized labelling of heterochromatic foci, including the sex chromatin, in a small percentage of cells. The results are interpreted as evidence for the derivation of a sex chromatin body from an entire X chromosome which replicates late during the DNA synthetic period.

ISSN:1424-8581    

DOI:10.1159/000129780

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Both sexes of Microtus oregoni are gonosomic mosaics; the male with the OY/XY constitution, the female the XX/XO. The diploid chromosome number of 17 originally reported by Matthey (1956, 1958) holds true only for male germ cells (OY) and female somatic cells (XO). The male, which develops from an XY-zygote with 18 chromosomes, produces two kinds of gametes; one with the Y, the other with no sex element; the X has been eliminated from the spermatogonia. Thus in this species the sperm with no sex element at all is female-determining; the XO-zygote develops into a female lacking a paternal X-chromo-some.

ISSN:1424-8581    

DOI:10.1159/000129781

出版商:S. Karger AG    

年代:1963

数据来源: Karger

摘要:

Chromosome counts and karyotype data are presented for three species and two subspecies of the Hominoidea and two species of gibbon (Hylobates). The results are compared with the human chromosome set. Pongo pygmaeus (the orangutan), Gorilla gorilla gorilla and Gorilla gorilla beringei (the lowland and mountain gorillas); Pan troglodytes troglodytes and Pan troglodytes paniscus (the northern and pygmy chimpanzees) all have 48 chromosomes while man (Homo sapiens) has 46. The karyotypes differ most widely in the relative number of long acrocentric and metacentric chromosomes. Hylobates lar (Lar gibbon) and Hylobates moloch (Sunda Island gibbon) have 44 chromosomes all of which are metacentric. These findings support the suggestion that the African great apes (Gorilla and Pan) are more closely related to man than the Asiatic apes (Pongo and Hylobates). It can be further suggested on the grounds of karyotype morphology that the gibbons (Hylobates and Symphalangus) should be classified in a separate family placed perhaps either in the Cercopithecoidea or Hominoidea.

ISSN:1424-8581    

DOI:10.1159/000129782

出版商:S. Karger AG    

年代:1963

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000129783

出版商:S. Karger AG    

年代:1963

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000129784

出版商:S. Karger AG    

年代:1963

数据来源: Karger