摘要:

Segregation behavior of a reciprocal translocation involving the long arm of chromosome No. 1 and a microchromosome was studied in secondary spermatocytes and embryos produced by heterozygous cockerels. The types and frequencies of the various balanced and unbalanced chromosome complements were determined. Complementary products of segregation did not occur in the expected ratios of 1:1 in secondary spermatocytes. The excess of spermatocytes with deficiency of the long arm and duplication of the short arm might be the result of lagging of the long arm at meiosis I, the centromere of the long arm being derived from a microchromosome. In the samples of secondary spermatocytes and embryos 52.5% and 49.6%, respectively, contained balanced chromosome complements. A significantly higher proportion of duplications and deletions of the long arm was seen in embryos than in secondary spermatocytes. Conversely, a lower proportion of duplications and deletions of the short arm was seen in embryos than in secondary spermatocytes. Apparently, spermatogenic cells bearing different unbalanced genomic contents are not equally viable or fertile.

ISSN:1424-8581    

DOI:10.1159/000132626

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Mouse chromosomes from the L929 cell line have been digested with the restriction endonuclease Haelll and analyzed by electron microscopy. Results show a different effect of the enzyme depending on the conditions of the digestion. Thus, while chromosomes digested in suspended cells show a double scaffold-like structure per chromatid, a similar banding to that found in chromosomes treated for light microscopy is obtained when chromosomes are digested on grids. Some aspects concerning the capacity of the cleaved DNA to be removed from the chromatin are discussed.

ISSN:1424-8581    

DOI:10.1159/000132627

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The KRAS2 gene was localized in the rabbit by chromosomal in situ hybridization, using a 3H-labeled human cDNA probe. There were 201 silver grains on 144 metaphase spreads; 12.9% of the grains resided on chromosome 16, and 54% of these grains were located close to the centromere at 16p11→q11. Statistical analysis indicated that labeling at this region represents a significant deviation from a random distribution and thus provided evidence for the assignment of KRAS2 to 16p11→q11. In addition to the predominant labeling site on 16, there was a positive signal at the telomere of 9q, possibly representing a sequence of another member of the ras family. Our assignment of KRAS2 to rabbit chromosome 16 strengthens the argument that a fragment on this chromosome is homoeologous to one on human chromosome 12, which bears the KRAS2 lo

ISSN:1424-8581    

DOI:10.1159/000132628

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The amino acid sequence of human prostate-specific antigen (APS) suggests that it is a member of the glandular kallikrein subfamily of serine proteases. In the mouse, the kallikrein-like family is localized in a single locus on chromosome 7, while other serine proteases are distributed over a variety of different chromosomes. To investigate the physical relationship between the human kallikrein genes, we have used in situ hybridization and Southern analysis of a human × mouse somatic cell hybrid panel to map the APS gene to 19q13, concordant with the renal kallikrein KLK 1 gene. This finding indicates that APS is a member of a human kallikrein-like gene family with analogous organization to that of the mouse

ISSN:1424-8581    

DOI:10.1159/000132629

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In situ hybridization was carried out using cloned satellite DNAs from the domestic cat and domestic dog as probes to metaphase chromosomes from 12 species of felids and 10 species of canids. Autoradiographic silver grains along metaphase chromosomes were counted and analyzed with regard to the mean number of grains per cell in each species, their chromosomal location, and their presence or absence on specific autosomes or sex chromosomes, where known. Among the felids and canids there was a 7.6- and 8.9-fold statistically significant difference, respectively, in the mean number of grains per cell between the species having the minimum and maximum values. Among the felids, most grains occurred on the telomeres of D- and E-group chromosomes, although departures from this general pattern also occurred. For example, the Asian golden cat and the Bornean bay cat showed substantial labeling at the centromeric region of chromosome Al, and a number of species showed some labeling at the short-arm telomeres of B-group chromosomes. Among the canids, about 90% of all grains were located at autosomal centromeres, and grains were absent from the sex chromosomes. Grains are usually distributed at chromosomal locations that stain C-band positive; however, certain C-band-positive regions without grains probably do not contain the particular satellites studied here.

ISSN:1424-8581    

DOI:10.1159/000132630

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Cloned satellite DNAs that hybridize primarily to C-band-positive regions of felid and canid chromosomes were used to probe the organization of satellite families in the genomes of 16 species of felids and 15 species of canids. Southern-blot and quantitative dot-blot experiments demonstrated that satellite families within the great cats (panthera lineage) vary considerably in regard to amount and/or sequence mismatch and vary some what in regard to restriction patterns. Satellite families within the canids appeared to be more uniform in regard to both amount/ sequence and restriction patterns, although some canid species did differ significantly from the consensus in both respects. Even though intrafamilial satellite restriction patterns were generally similar, every species could be shown to have a unique, characteristic pattern.

ISSN:1424-8581    

DOI:10.1159/000132631

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Localization of Epstein-Barr virus (EBV) DNA was studied by in situ hybridization on chromosomes from the Namalwa Burkitt lymphoma cell line and from a lymphoblastoid cell line transformed in vitro (ATL9/g). The five chromosome bands 1p32, 1q31, 5q21, 13q21, and 16p13 showed the presence of EBV DNA in both of the lines. Grain deposition at the site on chromosome 1 q of the Burkitt line was particularly intense. It was also found that EBV DNA in the lymphoblastoid cell line co-localized with a stable achromatic gap at 1p32 whose presence seems to confer a proliferative advantage on the cells.

ISSN:1424-8581    

DOI:10.1159/000132632

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

A 21-year-old Fanconi anemia patient developed refractory anemia. Laboratory studies revealed a transitory increased platelet count and a typical del(5q). Bone marrow karyo-typing showed a -6, + der(6)t(1;6)(q12;p25) rearrangement and, two years later, a mosaic-6,-1-der(6), t(1:6)(q12;p25)/-2, +der 2), t(l;2)(q12;q37) constitution. The chromosome mechanism operating in this patient is discussed.

ISSN:1424-8581    

DOI:10.1159/000132633

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Chromosomal rearrangements in three karyotypi-cally distinct, but morphologically and biochemically similar, races of rock wallabies (Petrogale) from North Queensland, Australia, were examined by C- and G-banding of cultured fibroblasts and by analysis of synaptonemal complexes from gonads of hybrid individuals. The assimilis race (2n = 20) had a submetacentric 6; 10 centric fusion, whereas the Mt.Claro(2n = 20) and Mareeba (2n = 18) races shared an identical submetacentric 5; 10 centric fusion. The 5 of this 5; 10 fusion was inverted in both races with respect to the free 5 of the assimilis race. Moreover, the Mareeba race had a unique acrocentric 6;9 fusion. Thus, while all three races are closely related, it is apparent from the chromosomal orientation that the Mareeba and Mt. Claro races are more closely related to each other than either is to the assimilis race.

ISSN:1424-8581    

DOI:10.1159/000132634

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The influence of maternal age on the incidence of aneuploidy and polyploidy was studied, using C57B1/6J × CBA/ Ca hybrid mice, including immature females, as gamete donors. The age of the females ranged from 3.5–4 wk (immature or prepubertal), to 10–12 wk (young adults), to 24–28 wk (aged females). Ovulation was induced with gonadotrophins, and the differential condensation of paternal and maternal chromosomes was used to elucidate the origin of chromosome abnormalities in first-division metaphase plates. The results indicated a high incidence of aneuploid oocytes in immature and older female mice, as compared to young adult females. Eggs of immature female mice underwent polyspermic fertilization more often than those of young adults and older females, and the production of diploid oocytes was more frequent in immature females than in the other age

ISSN:1424-8581    

DOI:10.1159/000132635

出版商:S. Karger AG    

年代:1988

数据来源: Karger