Showing papers on "Karyotype published in 1995"

Mosaicism of autosomes and sex chromosomes in morphologically normal, monospermic preimplantation human embryos.

Abstract: We have previously detected chromosome abnormalities in human embryos whilst identifying the sex for preimplantation diagnosis of X-linked disease. In this study we assess the incidence of these abnormalities, both for sex chromosomes and autosomes 1 and 17, using dual fluorescent in situ hybridization (FISH). Sixty-nine normally fertilized embryos of good morphology at the 6-10 cell stage (day 3 post-insemination) were examined. The embryos were spread whole using HCl and Tween 20 to dissolve the cytoplasm. Thirty-four embryos were analyzed for the sex chromosomes and 35 for autosomes 1 and 17. All probes were directly labelled with fluorochromes allowing analysis in 2 h. Control lymphocytes demonstrated that the probes were of high specificity. For the sex chromosomes, five embryos were mosaic (15 per cent) with the remaining 29 being uniformly XX or XY. In no case was an XX nucleus found in an otherwise XY embryo, indicating that even though mosaicism for the sex chromosomes is present, such abnormalities would not lead to a misdiagnosis of sex. For the autosomes, 16 embryos were abnormal (46 per cent); one embryo was triploid, one was monosomic for chromosome 1, and ten others were diploid mosaics (three diploid/aneuploid, three diploid/polyploid, and four diploid/haploid). A further four embryos had variable chromosome numbers in the majority of nuclei which appeared to be the result of uncontrolled mitotic division. The presence of haploidy or double monosomy, which occurred in 15 per cent of nuclei, has important implications for the diagnosis of trisomies and dominant disorders.

A comparative study of karyotypes of muntjacs by chromosome painting

Abstract: We have used a combination of chromosome sorting, degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), chromosome painting and digital image capturing and processing techniques for comparative chromosome analysis of members of the genus Muntiacus. Chromosome-specific “paints” from a female Indian muntjac were hybridised to the metaphase chromosomes of the Gongshan, Black, and Chinese muntjac by both single and three colour chromosome painting. Karyotypes and idiograms for the Indian, Gongshan, Black and Chinese muntjac were constructed, based on enhanced 4′, 6-diamidino-2-phenylindole (DAPI) banding patterns. The hybridisation signal for each paint was assigned to specific bands or chromosomes for all of the above muntjac species. The interspecific chromosomal homology was demonstrated by the use of both enhanced DAPI banding and comparative chromosome painting. These results provide direct molecular cytogenetic evidence for the tandem fusion theory of the chromosome evolution of muntjac species.

Telomere sequence localization and karyotype evolution in higher plants

Abstract: Data for chromosomal localization of theArabidopsis-type of telomeric sequence repeats (TTTAGGG)n are compiled for 44 species belonging to 14 families of angiosperms, gymnosperms and bryophytes For 23 species and seven families this is the first report Species of all families, except theAlliaceae, revealed these sequences at their chromosome termini This indicates thatArabidopsis-type telomeric repeats are highly conserved It is inferred that they represent the basic telomere sequence of higher plant phyla In theAlliaceae, a deviating sequence (and mechanism?) for the stabilization of chromosome termini has possibly evolved secondarily Nine species revealed interstitial telomeric sequences in addition to the terminal ones, in three species (Vicia faba, Pinus elliottii, P sylvestris) also at centromeric positions Interstitial telomeric sequences may indicate karyotype reconstructions, in particular alterations of chromosome numbers by chromosome fusion — or inversions with one breakpoint within the terminal array of repeats They may contribute to stabilization of chromosome breaks, especially centric fissions, and increase the frequency of meiotic and illegitimate recombination

Chromosome painting with human chromosome-specific DNA libraries reveals the extent and distribution of conserved segments in bovine chromosomes

Abstract: Commercially available human chromosome-specific DNA libraries covering the whole karyotype were hybridized to normal bovine metaphase spreads to characterize the conserved chromosomal segments between man and cattle. All chromosome libraries except the Y chromosome library displayed a signal on at least part of one or more bovine chromosomes. The labeling was clearly visualized and permitted precise delineation of the hybridized bovine chromosomal segments. This study indicates that the reorganization of the genetic material between human and bovine genomes is not as great as expected from classical comparative cytogenetics based on banding patterns. However, apart from interchromosomal rearrangements between ancestral forms of human and bovine chromosomes, a majority of intrachromosomal rearrangements must have occurred in these species during evolution to explain the differences in the banding patterns of their chromosomes. These results show that chromosome painting with heterologous chromosome-specific DNA libraries can provide useful information in comparative studies on karyotypes and gene maps of distantly related mammalian species. The observations are discussed in relation to published data on gene mapping in man and cattle.

Sex chromosome tetrasomy and pentasomy.

Abstract: Sex chromosome abnormalities occur in at least 1 in 400 births and include the well-described 47,XXX, 47,XXY, 47,XYY, and 45,X karyotypes. The addition of more than one extra X or Y chromosome occurs rarely, and little information is available in the medical literature. Individual case reports make up most of this body of knowledge, and all are based on subjects who identified themselves postnatally. Many were ascertained through screenings of institutions and hospitals; thus, there is no unbiased information on the natural history of poly X and Y karyotypes. A direct relationship between the number of additional sex chromosomes and the severity of the phenotype is generally assumed. The purpose of this article is to summarize what is known about these conditions and to present 10 additional cases. The karyotypes include, 48,XXXX, 49,XXXXX, 48,XXYY, 48,XXXY, 49,XXXXY, 49,XXXYY, 48,XYYY, 49,XYYYY, and 49,XXYYY.

Chromosome analysis of 97 primary breast carcinomas: identification of eight karyotypic subgroups.

Abstract: Chromosome banding analysis of 97 short-term cultured primary breast carcinomas revealed clonal aberrations in 79 tumors, whereas 18 were karyotypically normal. In 34 of the 79 tumors with abnormalities, two to eight clones per case were detected; unrelated clones were present in 27 (34%) cases, whereas only related clones were found in seven. These findings indicate that a substantial proportion of breast carcinomas are of polyclonal origin. Altogether eight abnormalities were repeatedly identified both as sole chromosomal anomalies and as part of more complex karyotypes: the structural rearrangements i(1)(q10), der(1:16)(q10;p10), del(1)(q11-12), del(3)(p12-13p14-21), and del(6)(q21-22) and the numerical aberrations +7, +18, and +20. At least one of these changes was found in 41 (52%) of the karyotypically abnormal tumors. They identify a minimum number of cytogenetic subgroups in breast cancer and are likely to represent primary chromosome anomalies in this type of neoplasia. Other candidates for such a role are translocations of 3p12-13 and 4q21 with various partner chromosomes and inversions of chromosome 7, which also were seen repeatedly. Additional chromosomal aberrations that give the impression of occurring nonrandomly in breast carcinomas include structural rearrangements leading to partial monosomies for 1p, 8p, 11p, 11q, 15p, 17p, 19p, and 19q and losses of one copy of chromosomes X, 8, 9, 13, 14, 17, and 22. The latter changes were seen consistently only in complex karyotypes, however, and we therefore interpret them as being secondary anomalies acquired during clonal evolution.

Allelic loss of sequences from the long arm of chromosome 10 and replication errors in endometrial cancers.

Abstract: Thirty-seven endometrial cancers were subjected to an allelotype analysis in an attempt to identify chromosomal regions that are lost in a significant portion of tumors and to identify tumors characterized by replication errors. Thirty-nine highly polymorphic microsatellite markers representing all chromosomal arms, excluding the X and the short arms of the acrocentrics, were examined. An average of 20 informative cases were evaluated for each marker. Genetic alterations were detected in 30 of the 37 tumors. Replication errors were identified in 8 tumor specimens. Loss of heterozygosity was observed for loci on all chromosomes examined with the exception of chromosomes 4 and 20. The two most frequent sites of loss were at the marker loci examined on 10q (40%) and 17p (29%). Six additional simple sequence repeat markers from 10q were genotyped in an effort to refine the region of 10q loss. The chromosome 10 markers used in these studies were physically mapped with the use of a panel of somatic hybrids that retain defined portions of chromosome 10. The observed patterns of loss of sequences on 10q suggest a role for a tumor suppressor gene in the 10q23-26 region in the development or progression of endometrial cancers.

Chromosome specific paints from a high resolution flow karyotype of the mouse.

Abstract: Using peripheral blood lymphocyte cultures and duallaser flow cytometry, we have routinely obtained high-resolution bivariate flow karyotypes of the dog in which 32 peaks are resolved. To allow the identification of the chromosome types in each peak, chromosomes were flow sorted, amplified and labelled by polymerase chain reaction with partially degenerate primers and hybridized onto metaphase spreads of a male dog. The chromosome paints from 22 of the 32 peaks each hybridized to single homologue pairs and eight peaks each hybridized to two pairs. Paints from the remaining two peaks hybridized to only one homologue each in the male metaphase spread, thus corresponding to the sex chromosomes X and Y. All of the 38 pairs of autosomes and the two sex chromosomes of the dog could be accounted for in these painting experiments. The positions of chromosomes 1–21 were assigned to the flow karyotype (only chromosomes 1–21 have as yet been officially designated). The high-resolution flow karyotype and the chromosome paints will facilitate further standardization of the dog karyotype. The ability to sort sufficient quantities of dog chromosomes for the production of chromosome-specific DNA libraries has the potential to accelerate the physical and genetic mapping of the dog genome.

Ring chromosomes in dermatofibrosarcoma protuberans are composed of interspersed sequences from chromosomes 17 and 22.

Abstract: Ring chromosomes are found in most dermatofibrosarcoma protuberans (DFSPs), and recent reports demonstrate that portions of the DFSP ring chromosomes derive from chromosome 17. In this study we characterized ring chromosomes in three DFSPs using a combined approach of karyotyping, chromosome painting, and comparative genomic hybridization. Chromosome painting demonstrated that the ring chromosomes in each DFSP were composed of discontinuous, interwoven sequences from chromosomes 17 and 22. Amplification of chromosomes 17 and 22 sequences was confirmed in each of these cases by comparative genomic hybridization, and over-representation of chromosomes 17 and 22 sequences was also demonstrated by comparative genomic hybridization in 1 of 2 cytogenetically unremarkable DFSPs. We conclude that amplification of chromosomes 17 and 22 sequences, in ring form, is a characteristic aberration in DFSP.

ZOO-FISH analysis: cat and human karyotypes closely resemble the putative ancestral mammalian karyotype.

Abstract: DNAin situ hybridization with human chromosome specific DNA libraries was applied to compare the karyotypes of humans(Homo sapiens, 2n=46) and cats(Felis catus, 2n=38). For the autosomes alone, 30 segments of conserved synteny were revealed. The arrangement of these segments in the feline karyotype differs by only seven single chromosome breaks and one intrachromosomal inversion from their arrangement in humans. Comparison of these data with those recently obtained for pig and those available from conventional gene mapping studies in mice and cattle has allowed us to develop a model of karyotype evolution in mammals. The cat and human karyotypes, with 36 and 44 autosomes respectively, were found to be very similar to a putative ancient mammalian founder karyotype. It would appear that during evolution to the human karyotype the status quo has been conserved for at least some 100–120 million years. There has been no need to alter the well-balanced gene arrangement of the mammalian founder karyotype.

Karyotypic characterization of colorectal adenocarcinomas

Abstract: Cytogenetic analysis of short-term cultures from 52 primary colorectal adenocarcinomas revealed clonal chromosome aberrations in 45 tumors, whereas the remaining 7 had a normal karyotype. More than 1 abnormal clone was detected in 26 tumors; in 18 of them, the clones were cytogenetically unrelated. The modal chromosome number was near-diploid in 32 tumors and near-triploid to near-tetraploid in 13. Only numerical aberrations were identified in 13 carcinomas, only structural aberrations in 3, and 29 had both numerical and structural changes. The most common numerical abnormalities were, in order of decreasing frequency, gains of chromosomes 7, 13, 20, and Y and losses of chromosomes 18, Y, 14, and 15. The structural changes most often affected chromosomes 1, 17, 8, 7, and 13. The most frequently rearranged chromosome bands were, in order of decreasing frequency, 13q10, 17p10, 1p22, 8q10, 17p11, 7q11, 1p33, 7p22, 7q32, 12q24, 16p13, and 19p13. Frequently recurring aberrations affecting these bands were del(1)(p22), i(8)(q10), i(13)(q10), and add(17)(p11-13). The most common partial gains were from chromosome arms 8q, 13q, and 17q and the most common partial losses from chromosome arms 1p, 8p, 13p, and 17p. A correlation analysis between the karyotype and the clinicopathologic features in our total material, which consists of altogether 153 colorectal carcinomas, including 116 with an abnormal karyotype, showed a statistically significant association (P < 0.05) between the karyotype and tumor grade and site. Carcinomas with structural chromosome rearrangements were often poorly differentiated; well and moderately differentiated tumors often had only numerical aberrations or normal karyotypes. Abnormal karyotypes were more common in rectal carcinomas than in carcinomas situated higher up. Near-triploid to near-tetraploid karyotypes were more than twice as frequent in tumors of the distal colon as in those of the proximal colon and rectum. The cytogenetic data indicate that carcinomas located in the proximal colon and rectum, which often are near-diploid with simple numerical changes and cytogenetically unrelated clones, probably arise through different mechanisms than do tumors located in the distal colon, which more often have complex near-triploid to near-tetraploid karyotypes.

Consistent Chromosome Abnormalities in Adenocarcinoma of the Pancreas

Abstract: Little is known about the somatic genetic changes which characterize pancreatic adenocarcinoma. The identification of acquired genomic alterations would further our understanding of the biology of this neoplasm. We have studied 62 primary pancreatic adenocarcinomas obtained from surgical resections using classical cytogenetics and fluorescent in situ hybridization methods. Clonally abnormal karyotypes were observed in 44 neoplasms. Karyotypes were generally complex (greater than three abnormalities) and included both numerical and structural chromosome abnormalities. Many tumors contained at least one marker chromosome. The most frequent whole chromosomal gains were chromosomes 20 (eight tumors) and 7 (seven tumors). Losses were much more frequent: chromosome 18 was lost in 22 tumors followed in frequency by chromosomes 13 (16 tumors), 12 (13 tumors), 17 (13 tumors), and 6 (12 tumors). Structural abnormalities were frequent. Two hundred nine chromosome breakpoints were identified. Excluding Robertsonian translocations, the chromosomal arms most frequently involved were 1p (12); 6q (11); 7q and 17p (9 each); and 1q, 3p, 11p, and 19q (8 each). Portions of the long arm of chromosome 6 appeared to be lost in nine tumors. To determine whether the apparent losses of portions of 6q are real, four tumors with 6q deletions were hybridized with a biotin-labeled microdissection probe from 6q24-ter. Loss of one copy of this region was verified in three of four tumors. In addition, double minute chromosomes were identified in eight cases. To our knowledge, these represent the first primary specimens of pancreatic adenocarcinoma with cytogenetic evidence of gene amplification.

Differential staining with orcein, giemsa, cma, and dapi for comparative chromosome study of 12 species of australian drosera (droseraceae)'

Abstract: Differential stainings with orcein, Giemsa, CMA, and DAPI were compared in 12 species of Western Australian Drosera. Chromosome numbers of D. roseana, D. barbigera, D. leioblasta, D. oreopodion, D. mannii, D. walyunga, D. sewelliae, D. helodes, and D. echinoblasta are reported here for the first time. A marked difference regarding chromosome number was observed in Drosera dichrosepala (2n = 12) from that of the previous report (2n = 18). The karyotypes of the species showed commonly that degree of asymmetry in chromosome length was directly proportional to the mean chromosomal length whereas the number of chromosomes was inversely proportional. Bimodal karyotypes were observed in D. oreopodion, D. walyunga, D. barbigera, and D. echinoblasta, which perhaps resulted from interspecific hybridization of the former two and fragmentation in the latter two. Sat-chromosomes found in D. falconeri, D. sewelliae, D. helodes, and D. echinoblasta responded differently in differential staining. The C and fluorescent bands at the mostly terminal region revealed that maximum C-positive heterochromatin-rich segments, GC-rich segments, and AT-rich segments were accumulated at the ends of Drosera chromosomes. Some chromosomes could be identified by their specific staining property. On the basis of chromosome number and C- and fluorescent-banding pattern, we suggest that D. helodes and D. sewelliae are closely related. The genus Drosera L., with 90 species, belongs to the family Droseraceae, which has a world-wide distribution (Diels, 1906). About two-thirds of Drosera species grow in Australia (Kondo, Segawa, and Nehira, 1976). The Australian Drosera taxa are mostly endemic to local areas (Diels, 1906; Conn, 1980; Marchant and George, 1982; Kondo and Lavarack, 1984). Most of the earlier cytologists concentrated on a conventional orcein karyomorphological study of this genus (Kondo, 1966, 1969, 1970, 1973, 1976, 1984; Kondo, Segawa, and Nehira, 1976). Thus, an attempt was undertaken to clarify relationships among the Australian

Chromosomal evolution in bovids: a comparison of cattle, sheep and goat G- and R-banded chromosomes and cytogenetic divergences among cattle, goat and river buffalo sex chromosomes

Abstract: A G- and R-banding comparison of cattle (Bos taurus, 2n=60), goat (Capra hircus, 2n=60) and sheep (Ovis aries, 2n=54) chromosomes at the 450 band level was made. The study revealed a large number of banding homologies among the autosomes of the three species and resolved some ambiguities in arranging some of their small disputed acrocentrics by direct and indirect comparisons with some bovid marker chromosomes. A loss of the subcentromeric G-positive band in sheep chromosome 2q was observed when the G-banding patterns of sheep 2q and homologous cattle and goat chromosome 2 were compared. The chromosomal divergences among cattle, goat and river buffalo (Bubalus bubalis, 2n=50) sex chromosomes are shown to have occurred by pericentric and paracentric inversions with a loss (or acquisition) of constitutive heterochromatin.

Cytogenetic, Molecular Genetic and Pathological Analyses in 126 Meningiomas

Abstract: In a series of 126 meningiomas, tumor and patient characteristics were investigated and statistically analyzed. A combined cytogenetic and molecular genetic approach was used to study chromosomal abnormalities and loss of markers on chromosome 22q. This approach was successfully applied to 93 meningiomas. In 66 cases, complete or partial loss of chromosome 22 was observed and in at least 12 of them this chromosome was involved in structural aberrations. In addition to chromosome 22 changes, chromosomes 1, 6, 11, 13, 14, 18, 19, X, and Y were also frequently involved in structural and numerical aberrations. Statistical analysis revealed a significant association between the number of chromosomal abnormalities and tumor grade. Complex karyotypes predominated in the group of grade II/III meningiomas. Furthermore, other variables showed statistically (or marginally statistically) significant differences. Meningiomas from the convexity were more often grade II/III, displayed predominantly (partial) loss of chromosome 22 and had complex karyotypes more often. These features were frequently found in meningiomas from males. Base meningiomas, on the other hand, occurred more often in females; they were usually grade I, showed loss of (parts of) chromosome 22 less often and displayed fewer additional chromosomal abnormalities.

Chromosomes and nuclear dna of crustacea

Abstract: Summary Present knowledge about chromosomes and nuclear DNA of Crustacea is reviewed. Haploid chromosome numbers range from 3 (Acanthocyclops) to 188 (Astacus). Chromosomes are generally small to medium in size (1–5 μm) and punctiform or rod-shape. Nuclear DNA amounts show a large range, lying between 0.37 (Daphnia) and 22.6 pg (Decapoda) per haploid genome, 5.5 × 108 nt to 1.8 × 1010 nt. Highly repetitive sequences may represent as much as 30% of the genome and show a high degree of conservation in Brachyura, while some intermediate repetitive sequences are under-represented. The relationship between taxonomy and cytogenetics appears very complex in some taxa, such as Artemia (Branchiopoda). This genus includes bisexual sibling species with female heterogamety and parthenogenetic populations with different levels of ploidy, up to triploid and pentaploid. Daphnia presents diploid and polyploid strains, and parthenogenetic reproduction. Chromatin diminution occurs in Copepoda; in this group male and female...

Molecular cytogenetic analysis of the double-CMA3 chromosome of lake trout, Salvelinus namaycush.

Abstract: The chromosome possessing two chromomycin A3 (CMA3) staining sites in lake trout (Salvelinus namaycush) was examined using FISH. All CMA3-bands in the karyotype contained ribosomal DNA (rDNA), including both sites on the double-CMA3 chromosome. One rDNA site on this chromosome was bordered by telomeric repeats, implicating a rearrangement in the origin of the second NOR.

Establishment and characterization of four human medulloblastoma-derived cell lines.

Abstract: We have established four cell lines, UW228-1, UW228-2, UW228-3 and UW443, from two posterior fossa medulloblastomas The three UW228 sublines originated from a tumor with a diploid DNA content, while the tumor of origin of UW443 was predominantly tetraploid Both tumors displayed areas of immunopositivity for synaptophysin and glial fibrillary acidic protein All four cell lines have been grown as monolayers in continuous culture for 50 to 200 passages, are not contact inhibited at high density, and form colonies in soft agar The UW228 sublines are aneuploid, have similar modal chromosome numbers, similar chromosomal duplications and identical marker chromosomes, and display loss of heterozygosity for identical sequences at the distal end of chromosome 17p UW443 is diploid and also shows loss of heterozygosity for a distal sequence on chromosome 17p All lines are immunopositive for two or more neurofilament proteins, three lines (UW228-1, UW228-2 and UW443) are immunopositive for synaptophysin, and none are immunopositive for glial fibrillary acidic protein The lines differ in sensitivity to the alkylating agents 1,3-bis(2-chloroethyl)-1-nitrosourea and N-methyl-N'-nitro-N-nitrosoguanidine They also differ in dependence on the DNA repair protein O6-methylguanine-DNA methyltransferase for alkylating agent resistance and in levels of the DNA repair activities apurinic/apyrimidinic endonuclease and DNA polymerase beta These properties establish UW228-1, UW228-2, UW228-3 and UW443 as four new, phenotypically distinct medulloblastoma-derived cell lines

Nonrandom Chromosome Abnormalities in Short-Term Cultured Primary Squamous Cell Carcinomas of the Head and Neck

Abstract: We report the finding of clonal chromosome abnormalities in shortterm cultures from 44 squamous cell carcinomas of the head and neck region. Eleven tumors had gain or loss of the Y chromosome, sometimes one clone with +Y and another with — Y, as the sole anomaly, whereas the remaining 33 all carried structural rearrangements and usually were cytogenetically complex with multiple aberrations. The chromosomal bands most frequently involved were, in decreasing order of frequency, 8pll-qll, Ipll-qll, 3pll-qll, Ilql3, 13pll-qll, Ipl3, Spll-qll, 7pllqll, 15pll-qll, and 14pll-qll. Almost one-half of the breakpoints were located in centromeric or juxtacentromeric bands. Recurrent aberrations included i(8q), i(5p), iilqi. del(3)(pll-12), del(5)(pll), t(l;l)(pl3;q25), and der(14;15)(q!0;qlO). To see whether the karyotypic features of head and neck squamous cell carcinoma differ depending on exact tumor site, we added to the present series our previously published 23 karyotypically abnormal head and neck squamous cell carcinomas that had been cul tured in the same way as the tumors of the present series. In the ensuing correlation analysis, tumors of the oral cavity and oropharynx and hypopharynx were found to share many features: highly complex karyotypes were frequent, often containing isochromosomes such as i(8q) and i(5p), and also rearrangements of I Iql.l (often as homogeneously staining re gions) and loss of genetic material from the short arms of chromosomes 3, 13, 14, and 15 were repeatedly seen. Laryngeal carcinomas, on the other hand, often had simple karyotypic changes.