摘要:

Both light and electron microscopy were used to study the pairing behavior of the sex chromosomes of the harvest mouse, Micromys minutus, in surface-spread pachytene spermatocytes. The XY pairing pattern is very exceptional in that the site of synaptic initiation is located interstitially in the short arms of the X and the Y, next to their centromeric-regions. From this tiny euchromatic site, synapsis proceeds unidirectionally along the homologous heterochromatic short arms of the X and the Y toward the ends of the chromosomes. After pairing of the short arm is concluded, synapsis begins between the nonhomologous long arms of the X and the Y in the immediate vicinity of the centromeres and progresses unidirectionally toward the end of the long arm of the Y. A synaptic complex develops between the constitutive heterochromatin of the long arm of the Y and the euchromatin of the long arm of the X. Analysis of C-banded and distamycin A/DAPI-stained diakineses revealed a trefoil-like XY bivalent, which was interpreted to be the result of an interstitial chiasma occurring in the paired short arms of the X and the Y. A conspicuous, electron-dense body, about 1 µm in diameter, was found closely associated with the centromeres of the X and the Y in numerous pachytene spermatocytes. A review of the literature showed that comparable XY-associated bodies have been found in only eight other mammals to date

ISSN:1424-8581    

DOI:10.1159/000132443

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

The centromeric-paracentromeric regions of high-resolution human chromosomes have not been examined in detail. It is not clear which bands in the paracentromeric regions are included within the heterochromatin and are therefore not clinically meaningful, and which bands are excluded. This makes breakpoint analysis in these regions difficult. Using sequential G- and C-banding of high-resolution chromosome preparations from four clinically normal subjects and from one patient with a very small interstitial deletion of the chromosome 16 long arm, we have made a detailed analysis of the centromeric-paracentromeric regions of each chromosome and of the entire Y chromosome at the 400, 550, and 800–850 band stages. We present here the results of analysis of preparations at the 800–850 band st

ISSN:1424-8581    

DOI:10.1159/000132444

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

A system is proposed whereby human karyotype data is expressed in quantitative terms rather than in the ISCN (1985) terminology used at present. This recoding facilitates application of multivariate analysis using standard statistical packages. As an example, karyotypes of 714 cases from 11 leukemias (Mitelman, 1983) are here recoded and subjected to discriminant analysis (SPSSx, 1983). Significant karyotypic specificity is apparent in six of the 11 FAB leukemia types. Four others show insignificant levels of specificity, while the last is equivocal. These results merely confirm present views. However, their generation by means of computerized multivariate analysis is novel, and confirms the feasibility of the approach. In this quantitative form, karyotypic data may be combined with any other data of diagnostic or prognostic value. Given such a consolidated data set, desired information concerning any aspect of neoplasia could be extracted via a single procedure.

ISSN:1424-8581    

DOI:10.1159/000132445

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

A specific chromosomal abnormality, t(2;13)(q35;q14), was discovered in five cases of advanced rhabdomyosarcoma. It was identified directly in cells that had metastasized from bone marrow in one patient and in xenografts derived from the tumors of four other patients. The translocation was not restricted by histologic subtype, but was found in cases classified as alveolar, undifferentiated, or embryonal. Cytogenetic hallmarks of gene amplification (double minute chromosomes and homogeneously staining regions) were apparent in three cases. Other frequent abnormalities included rearrangements of chromosome 1p and trisomy of chromosome 8. The absence of the t(2;13) in more than 100 cases of other pediatric solid tumors investigated in our laboratory indicates its specificity for rhabdomyosarcoma. These cytogenetic findings suggest directions for further investigation of the molecular events underlying the genesis of this tumor.

ISSN:1424-8581    

DOI:10.1159/000132446

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Expression of three distinct human cell surface antigens defined by monoclonal antibodies (mAbs) was examined in a series of rodent-human somatic cell hybrids retaining different subsets of human chromosomes. Cell surface reactivity with mAbs F8 and G253, detecting a 95 kilodalton (kD) glycoprotein (gp95); with mAbs F10 and A103, detecting a 50 kD glycoprotein (gp50); and with mAb S7 was found to cosegregate with human chromosome 19. However, differential antigen expression was observed with hybrids containing fragments of the 19 and hybrids constructed with different human cell types. Comparison of results from the serological typing with the presence of a number of chromosome 19 DNA markers in hybrid cells and cytogenetic analysis suggests that MSK20, the gene coding for the F10/A103 antigen gp50, is located in chromosome region 19pter→19p13.2. The genes coding for the F8/G253 antigen, gp95 (gene symbol MSK19) and the S7 antigen (MSK37) are located in region 19p13.2→19q13.2. Thus, the cell surface antigens described in this study may be used as selectable markers for specific portions of human chromosome

ISSN:1424-8581    

DOI:10.1159/000132447

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Two unrelated chromosome abnormalities were found in equine half sibs. The proposita, Case 1, which was short in stature and infertile, had a de novo unbalanced X;15 translocation involving loss of Xp. Replication studies indicated that the translocated X was preferentially late replicating and that this late replication spread variably into the autosomal segment. Case 2, a half brother of the proposita, was short in stature, had cryptorchidism, and was trisomic for chromosome 28. Cytogenetic analysis of the dam, the sire of Case 1, and two other phenotypically normal half sibs revealed normal chromosome complements. Five further normal pregnancies were reported. The finding of two unrelated chromosome abnormalities is therefore probably fortuitous in this family. This is the first case of an unbalanced X-autosome translocation and the first case of an autosome trisomy to be reported in the horse.

ISSN:1424-8581    

DOI:10.1159/000132448

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Premature chromosome condensation of G1 G2, and S-phase chromosomes has been achieved by the use of electrofusion in the fusion of Chinese hamster ovary (CHO) cells and HeLa cells and CHO cells with human leukocytes. Very high yields of heterokaryons, of over 80%, as well as elimination of adverse effects of chemical and viral fusion agents, facilitated induction of premature chromosome condensation of high quality.

ISSN:1424-8581    

DOI:10.1159/000132449

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Mouse Pvt-1 and rat MISl are frequent proviral integration sites in retrovirally induced lymphomas. The Pvt-1 locus is also involved in mouse plasmacytoma (6;15) and in the variant Burkitt lymphoma (2;8) translocations. We show that the Pvt-1/MISl locus is syntenic with MYC on rat chromosome 7. This is consistent with a postulate of close linkage and, possibly, a functional relationship between the MYC protoon-cogene and the MIS1/Pvt-1 locus.

ISSN:1424-8581    

DOI:10.1159/000132450

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

We investigated the relationships between subspecies of Nyctereutes procyonoides from China (2n = 54 + B chromosomes) and Japan (2n = 38 + B chromosomes). The chromosomes of Chinese and Japanese raccoon dogs were compared by means of conventional staining, G- and C-banding, and silver nitrate staining of NORs. Extensive G-banding homologies revealed karyotype evolution through chromosomal fusion. We believe the reduced diploid number in the Japanese raccoon dog was achieved by fusion of 16 acrocentrics to form eight metacentric and submetacentric elements. Ten pairs of autosomes appeared to be identical in these subspecies and were presumed to have occurred as such in a common ancestor. G-band patterns of the sex chromosomes were similar in the two subspecies, but differences were noted with other banding and staining techniques. B chromosomes were present in varying numbers and sizes in all animals examined, but the morphology of the B chromosomes differed in the two subspecies. It was concluded from chromosomal and paleontological evidence that the two subspecies were derived from a common mainland ancestor and that the Japanese raccoon dog is a relatively recent form.

ISSN:1424-8581    

DOI:10.1159/000132451

出版商:S. Karger AG    

年代:1987

数据来源: Karger

摘要:

Nine of 40 pleomorphic salivary gland adenomas (PSAs) showed clonal aberrations of chromosome 12, with a breakpoint at 12q13→q15. The cytogenetic findings in these cases and those of nine additional cases reported in the literature suggest that this type of aberration is a primary change directly involved in the genesis of PS

ISSN:1424-8581    

DOI:10.1159/000132452

出版商:S. Karger AG    

年代:1987

数据来源: Karger