摘要:

Cytogenetic studies of somatic cells in the chamois, belonging to the tribe Rupicaprini of the family Bovidae, revealed a karyotype with 58 acrocentric chromosomes and with one pair of large metacentrics. The fundamental number of 60 and the presence of Robertsonian changes as a dominating mechanism of karyotype variation seem to be characteristic for the tribe Rupicaprini, as they are for some related tribes of the Bovidae, mainly the Caprini.

ISSN:1424-8581    

DOI:10.1159/000130073

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Cytogenetic studies were made in dark-colored wild mice, previously described as M. poschiavinus Fatio, 1869. These mice are found only at a single locality, a Swiss high-altitude valley, the Val Poschiavo/Grisons. The karyotype is characterized by the presence of 26 chromosomes, with seven pairs of meta-centrics, five pairs of acrocentric autosomes and the acrocentric sex-chromosomes (2n = 26; N.F. = 40). The F1 resulting from crossbreeds of M. poschiavinus and the laboratory mouse has invariably a somatic set of 33 chromosomes, 7 metacentrics and 26 aerocentrics (2n = 33; N.F. = 40). Meiotic diakinesis figures of the F1 show seven trivalents, five bivalents and one end-to-end-associated X-Y bivalent. M. poschiavinus, M. musculus and their hybrids seem to display an ideal Robertsonian variation. However, there is marked reduction of fertility in the F1 and in subsequent generations. The analysis of meiotic metaphase II in the male leads to the assumption that meiotic nondisjunction and embryonic aneuploidy are a major cause of the reduced fertility. The infrequent and small litters in the hybrid generations probably represent the viable products of only the balanced genetic combinations. The sequence of Robertsonian fusions that have led to the actual karyotypic conditions in M. poschiavinus seems to have built up an effective barrier, providing cytologic isolation of this species and securing its coexistence with M. musculus. The system of chromosomal variation in M. poschiavinus and its hybrids with the laboratory mouse provides an appropriate material for studies of phenotype variation and of genetic control of biochemical markers.

ISSN:1424-8581    

DOI:10.1159/000130074

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

So as to clarify the conflicting data on the chromosome number of human endometrium, endometrial cells from six normal women and four patients with uterine bleeding were cultured in vitro in serial tissue culture, omitting trypsin, CO2 incubation and human serum. Based on chromosome studies of 5,301 dividing cells, including determinations of exact chromosome numbers of 2,242 metaphases and estimations of ploidy levels and complete karyotype analysis of 332 cells, normal human endometrium was shown to have the same chromosome number as other human tissues. Furthermore, the chromosomal constancy was the same as in normal skin tissue. Polyploidy incidence was higher in three patients with bleeding, and one of them had a higher degree of aneuploid variation. One patient with fibroma had only near-tetraploid cells in the sample of endometrium studied. A statistical analysis of aneuploid cells with 45 chromosomes suggested that the losses were nonrandom.

ISSN:1424-8581    

DOI:10.1159/000130075

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Satellite association (SA) in lymphocytes obtained from women was found in 89.9% of cells after 48 h in culture and in 66.1% of cells after 96 h. After 48 h, 33.7% of acrocentrics participate in SA, whereas 30.7%, and 17.7% participate after 72 and 96 h. Prophase through prometaphase nucleoli were found in 26.8% of cells after 48 h and in 13.1% of cells after 96 h. SA and mitotic nucleoli are most common in 48 h cultures, and both decrease with increasing in vitro duration. These findings suggest a relationship between nucleolar persistence and SA.

ISSN:1424-8581    

DOI:10.1159/000130076

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

A karyotypic and autoradiographic study was undertaken in an effort to identify the Y chromosome in five subspecies of the deer mouse, Peromyscus maniculatus. Three cells from each of seven male animals were analyzed. Although three of the animals were from the same subspecies and two were from the same location, all seven animals had different karyotypes. The existence of large groups of similar chromosomes, more than one heteromorphic pair of chromosomes or cell-to-cell variation within an animal precluded karyotypic identification of a Y in four animals. However, in all seven animals a probable Y could be designated from autoradiography since one chromosome consistently completed DNA replication later than the rest of the complement. The Y as identified by karyotyping corresponded to the latest labeling chromosome in only two animals. Observations are also presented on the proposed X in males.

ISSN:1424-8581    

DOI:10.1159/000130077

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

A sterile male German shorthair pointer with testicular hypoplasia and a ventricular septal defect was found to have a 79, XXY chromosome constitution in peripheral-blood leukocytes, bone marrow and fascia lata fibroblasts. The presence of a late-labeling X chromosome in peripheral-blood leukocytes was demonstrated by autoradiographic studies. This is the first report of the occurrence of the XXY condition in a dog.

ISSN:1424-8581    

DOI:10.1159/000130078

出版商:S. Karger AG    

年代:1970

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130079

出版商:S. Karger AG    

年代:1970

数据来源: Karger