摘要:

Nine phenotypically normal gilts were slaughtered on the 25th day following coitus, and the embryos were harvested and cultured for karyotypic analysis. A total of 76 embryos were recovered, 8 of which were dead and in various stages of degeneration. The mean ovulation rate, based on a corpora lutea count, was 11.8 ± 0.6. Prenatal death loss, based on the ratio of embryos harvested to corpora lutea count, was estimated at 35.8 %. The diploid number of 38 chromosomes was found in 90.2 % of 797 cells counted. Karyotypic analyses revealed only one abnormal embryo, which was monosomic for pair 16. However, lethal chromosome combinations could not be ruled out as the cause of cell death in the eight dead embryos. If chromosomal abnormalities are relatively constant in nature, these results would indicate that most abnormal embryos rarely survive implantation

ISSN:1424-8581    

DOI:10.1159/000130159

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

A brief exposure of cells to Colcemid induces chromosomal nondisjunction. Making use of this behavior, we isolated several trisomic as well as monosomic cell clones from a cloned pseudodiploid Chinese hamster cell line. Karyotype analyses of these clones demonstrated that mainly small chromosomes such as Nos. 9 and 10 (or No. 11) were involved in chromosomal addition or loss. Nondisjunction was found to occur randomly in every member of the complement, but progeny cells possessing unbalanced chromosome constitutions, such as aneusomies of large chromosomes, appeared to die off or undergo karyotype remodeling by the time of the third or fourth mitosis after induction of nondisjunction.

ISSN:1424-8581    

DOI:10.1159/000130160

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

Double monosomy mosaicism was observed in a three-year-old girl who had mental and physical retardation. Routine blood-lymphocyte and bone-marrow chromosome studies showed an apparent 45, X pattern, which was confirmed by autoradiographic studies with tritiated thymidine. Routine and fluorescent chromosome analyses from bilateral skin biopsies revealed a 45,XX,21– karyotype, which was consistent with the positive sex-chromatin pattern in these fibroblasts as well as in the buccal smear and hair-root-sheath cells. Although her clinical features bore some resemblance to patients with Turner’s syndrome and to patients with G monosomy, our patient did not closely fit either of these syndro

ISSN:1424-8581    

DOI:10.1159/000130161

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

A five-year-old girl with mild mental retardation and dyschondrosteosis was found to have 45 chromosomes. A G (21-22) chromosome was missing. The parents were chromosomally normal. Measurements confirmed the presence of an unusually long chromosome No. 17 or 18 in the girl’s karyotypes. Late labeling with 3H-thymidine and autoradiography showed it to be No. 18. By quinacrine fluoromicroscopy the apparently missing G chromosome proved to be No. 21. Thus, the apparent autosomal monosomy was the result of a de novo 18/21 translocation with loss of the short arm and centromere of No. 21 and of material from the long arms of No. 18 or No. 21 or both equivalent to two thirds of a G long arm. Although no evidence was found for deletion of a genetic marker, heterozygosity at five gene loci (MNSs, Jk, Hp, PGM, and AcP) excluded their deletion. We suggest that other instances of apparent autosomal monosomy may on careful study be found to be the result of similarly subtle chromosome rearrangement

ISSN:1424-8581    

DOI:10.1159/000130162

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

Autoradiographic terminal labeling studies performed on leukocyte cultures of a man (A. de J.) and his son (H. de J.), both carriers of an enlarged satellite on a D-group chromosome, demonstrated that the morphological marker was a No. 15. Counts of grains on the long arms of the two chromosomes 15 showed that the marker chromosome was less heavily labeled than its normal homolog. This difference was highly significant in both cases. The marker chromosome was also shorter than its homolog, though not significantly so in one case. Possible interpretations of these findings, i.e., chromosomal polymorphism or autosomal lyonization, were discussed.

ISSN:1424-8581    

DOI:10.1159/000130163

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

In the mouse, virtually every autosome pair, and the X and Y, was identified by its distinctive fluorescent banding pattern after staining with quinacrine mustard. The karyotype was characterized further by measurement of orcein-stained chromosomes and autoradiographic analysis of terminal DNA replication. The autoradiographic identification of the X and Y chromosomes was confirmed by this technique. Fluorescent karyotype analysis of inbred strains and a series of Fx hybrids involving C57BL/6J revealed a polymorphism, the presence or absence of a prominent secondary constriction on any of four different chromosomes, which was probably inherited in a simple Mendelian fashion.

ISSN:1424-8581    

DOI:10.1159/000130164

出版商:S. Karger AG    

年代:1971

数据来源: Karger

摘要:

The mitotic chromosomes in primary embryonic cultured cells of eight translocation stocks of Mus musculus were identified by their distinctive fluorescent banding patterns after staining with quinacrine mustard. By correlation of cytologic and genetic information, linkage group (LG) X was assigned to chromosome 7 and LG VIII to chromosome 5. Several earlier assignments were confirmed: LG I to chromosome 8, LG V to chromosome 2, LG XII to chromosome 19, LG XIII to chromosome 1, and LG XVIII to chromosome 9. In addition, chromosomes 4, 17, and 18 were identified in translocations, but the available genetic data did not permit linkage-group assignments. The centromere of chromosome 8 was located at the nv (Nijmegen waltzer) end of LG I by the two-breakpoint method. The position of the centromere of chromosome 1 at the fz (fuzzy) end of LG XIII and that of chromosome 9 at the nr (nervous) end of LG XVIII were confirmed by the same method.

ISSN:1424-8581    

DOI:10.1159/000130165

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130166

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130167

出版商:S. Karger AG    

年代:1971

数据来源: Karger

ISSN:1424-8581    

DOI:10.1159/000130168

出版商:S. Karger AG    

年代:1971

数据来源: Karger