Showing papers on "Karyotype published in 1996"
TL;DR: Whole-genome scanning by spectral karyotyping allowed instantaneous visualization of defined emission spectra for each human chromosome after fluorescence in situ hybridization, and all human chromosomes were simultaneously identified.
Abstract: The simultaneous and unequivocal discernment of all human chromosomes in different colors would be of significant clinical and biologic importance. Whole-genome scanning by spectral karyotyping allowed instantaneous visualization of defined emission spectra for each human chromosome after fluorescence in situ hybridization. By means of computer separation (classification) of spectra, spectrally overlapping chromosome-specific DNA probes could be resolved, and all human chromosomes were simultaneously identified.
1,806 citations
TL;DR: The data suggest that multiplex-fluorescence in situ hybridization (M-FISH) could have wide clinical utility and complement standard cytogenetics, particularly for the characterization of complex karyotypes.
Abstract: We have developed epifluorescence filter sets and computer software for the detection and discrimination of 27 different DNA probes hybridized simultaneously. For karyotype analysis, a pool of human chromosome painting probes, each labelled with a different fluor combination, was hybridized to metaphase chromosomes prepared from normal cells, clinical specimens, and neoplastic cell lines. Both simple and complex chromosomal rearrangements could be detected rapidly and unequivocally; many of the more complex chromosomal abnormalities could not be delineated by conventional cytogenetic banding techniques. Our data suggest that multiplex-fluorescence in situ hybridization (M-FISH) could have wide clinical utility and complement standard cytogenetics, particularly for the characterization of complex karyotypes.
1,333 citations
TL;DR: To be able to provide proper counselling for those couples whose male infertility can now be treated by intracytoplasmic sperm injection, it is suggested that clinical investigations should include mitotic and meiotic studies, an analysis of the chromosome content of individual spermatozoa and a DNA analysis of blood and spermatozosa to detect partially deleted Y chromosome material.
Abstract: Chromosomally derived sterility has long been recognized. A review of the literature of somatic chromosome investigations in infertile males has shown that 13.7% of azoospermic males and 4.6% of oligozoospermic males have an abnormal karyotype. In the first group, sex chromosome abnormalities predominate (mainly 47,XXY), whereas in the latter, autosome anomalies (i.e. Robertsonian and reciprocal translocations) are the most frequent. A similar review on meiotic studies revealed that meiotic chromosome anomalies can explain male infertility in 4.3-40.4% of patients. Recently, fluorescent in-situ hybridization studies on spermatozoa from infertile men were published; it was suggested that both X-Y pairing and pairing of the autosomes were impaired, resulting in spermatogenic disruption. We investigated cytogenetically 694 infertile men with abnormal sperm parameters. More patients are needed for this research to investigate the relationship, if any, between the type of chromosome abnormality and its influence on the number, morphology and motility of spermatozoa. To be able to provide proper counselling for those couples whose male infertility can now be treated by intracytoplasmic sperm injection, it is suggested that clinical investigations should include mitotic and meiotic studies, an analysis of the chromosome content of individual spermatozoa and a DNA analysis of blood and spermatozoa to detect partially deleted Y chromosome material.
516 citations
TL;DR: It is demonstrated that bidirectional heterologous chromosome painting is a highly efficient way of generating comparative cytogenetic maps.
441 citations
TL;DR: It is observed that crude aneuploidy and increased proliferative activity are early events in colorectal carcinogenesis, followed by TP53 overexpression and the acquisition of recurrent chromosomal gains and losses during the progression from high‐grade adenomas to invasive carcinomas.
Abstract: Comparative genomic hybridization was used to screen the DNA extracted from histologically defined tissue sections from consecutive stages of colorectal carcinogenesis for chromosomal aberrations. No aberrations were detected in normal epithelium (n = 14). Gain of chromosome 7 occurred as a single event in low-grade adenomas (n = 14). In high-grade adenomas (n = 12), and overrepresentation of chromosomes 7 and 20 was present in 30% of the cases analyzed. The transition to colon carcinomas (n = 16) was characterized by the emergence of multiple chromosomal aberrations. Chromosomes 1, 13, and 20 and chromosome arms 7p and 8q were frequently gained, whereas chromosome 4 and chromosome arms 8p and 18q were recurrently underrepresented. The same tissue sections that were used for CGH were analyzed by means of DNA-ploidy measurements and immunohistochemical staining to quantify proliferative activity and p21/WAF-1 and TP53 expression. We observed that crude aneuploidy and increased proliferative activity are early events in colorectal carcinogenesis, followed by TP53 overexpression and the acquisition of recurrent chromosomal gains and losses during the progression from high-grade adenomas to invasive carcinomas.
395 citations
TL;DR: Extended prophase I chromosomes, particularly at the pachytene stage, offer considerable potential for producing a detailed cytogenetic map (karyotype) ofArabidopsis chromosomes with the additional prospect of high-resolution physical mapping based on fluorescencein situ hybridization of defined DNA probes to these extended chromosomes.
Abstract: An atlas of meiosis in Arabidopsis thaliana, encompassing all stages from preleptotene to telophase II and early microspore formation, is presented in detail for the first time. The photomicrographs and descriptions are based on staining with the DNA fluorochrome 4',6-diamidino-2-phenylindole (DAPI) combined with a spreading procedure, or haematoxylin-iron alum (HIA) staining. Despite previous reservations about the practicality of cytogenetic meiotic analysis in Arabidopsis due to its small genome size, good-quality and clearly analysable preparations of all meiotic stages were obtained. This atlas of normal, wild-type meiosis is considered an essential prerequisite to informed analyses of meiotic mutants. Furthermore, extended prophase I chromosomes, particularly at the pachytene stage, offer considerable potential for producing a detailed cytogenetic map (karyotype) of Arabidopsis chromosomes with the additional prospect of high-resolution physical mapping based on fluorescence in situ hybridization (FISH) of defined DNA probes to these extended chromosomes.
342 citations
TL;DR: Spectral karyotyping (SKY) is applied to chemically induced plasmocytomas, mammary gland tumours from transgenic mice overexpressing the c-myc onco-gene and thymomas from mice deficient for the ataxia telangiectasia (Atm) gene to demonstrate the potential of SKY to identify complex chromosomal aberrations in mouse models of human carcinogenesis.
Abstract: Murine models of human carcinogenesis are exceedingly valuable tools to understand genetic mechanisms of neoplastic growth. The identification of recurrent chromosomal rearrangements by cytogenetic techniques serves as an initial screening test for tumour specific aberrations. In murine models of human carcinogenesis, however, karyotype analysis is technically demanding because mouse chromosomes are acrocentric and of similar size. Fluorescence in situ hybridization (FISH) with mouse chromosome specific painting probes can complement conventional banding analysis. Although sensitive and specific, FISH analyses are restricted to the visualization of only a few mouse chromosomes at a time. Here we apply a novel imaging technique that we developed recently for the visualization of human chromosomes to the simultaneous discernment of all mouse chromosomes. The approach is based on spectral imaging to measure chromosome-specific spectra after FISH with differentially labelled mouse chromosome painting probes. Utilizing a combination of Fourier spectroscopy, CCD-imaging and conventional optical microscopy, spectral imaging allows simultaneous measurement of the fluorescence emission spectrum at all sample points. A spectrum-based classification algorithm has been adapted to karyotype mouse chromosomes. We have applied spectral karyotyping (SKY) to chemically induced plasmocytomas, mammary gland tumours from transgenic mice overexpressing the c-myc oncogene and thymomas from mice deficient for the ataxia telangiectasia (Atm) gene. Results from these analyses demonstrate the potential of SKY to identify complex chromosomal aberrations in mouse models of human carcinogenesis.
304 citations
TL;DR: To examine the possible role of chromosome 3p deletions in the development of papillary RCC, 11 cases were studied for loss of heterozygosity (LOH) at one or more loci in the region of 3pl3–21, and the findings are discussed.
Abstract: Papillary renal cell carcinoma (papillary RCC) is an uncommon histologic variant of RCC with distinct gross, microscopic, and immunohistochemical features. Recent karyotypic analyses suggest that papillary RCC differs from other types of RCC at the genetic level as well. Whereas nonpapillary (clear cell, granular cell) RCC is characterized by deletions in chromosome 3p, papillary tumors reportedly exhibit a pattern of chromosomal trisomies, typically including chromosomes 7 and 17. To further examine the relationship between overrepresentation of these chromosomes and papillary histology, archival material from 36 papillary tumors was subjected to fluorescence in situ hybridization (FISH) analysis using alpha-satellite repeat probes specific to 7 and 17. Excess signals for chromosome 17 were detected in 22 of 28 (78%) low-grade papillary tumors (Fuhrman nuclear grades 1 and 2), and in seven of eight (87%) high-grade tumors (grades 3 and 4). Correlation of chromosome 17 FISH signals with karyotypes performed on two low-grade and three high-grade tumors was excellent. Among the cases without evidence of excess chromosome 17 were three unusual papillary tumors with sclerotic and hyalinized fibrovascular cores. In two cases, comparison was made of FISH signals from multiple, separate gross nodules of tumor; concordance for trisomic 17 signals was observed in one case, but not in the other. Chromosome 7 signals were overrepresented in all seven papillary tumors examined. DNA ploidy was determined in 19 of the 36 tumors; a relationship between DNA ploidy and polysomy 7 or 17 was not apparent. To examine the possible role of chromosome 3p deletions in the development of papillary RCC, 11 cases were studied for loss of heterozygosity (LOH) at one or more loci in the region of 3p13-21. Only three of the 11 cases had LOH at these loci. The findings are discussed with respect to the development and progression of papillary RCC.
213 citations
TL;DR: A translocation, t(17;22)(q22;q13), was identified in two cases of dermatofibrosarcoma protuberans (DP), which casts light on the development and significance in DP of ring chromosomes which consistently harbor sequences derived from chromosomes 17 and 22.
Abstract: A translocation, t(17;22)(q22;q13), was identified in two cases of dermatofibrosarcoma protuberans (DP). They bring to four the number of DP cases characterized by an identical t(17;22)(q22;q13), which can be considered as a new tumor-associated chromosome rearrangement. To date, this translocation has been found only in DP and its juvenile form, giant-cell fibroblastoma. This finding has two major consequences. First, it casts light on the development and significance in DP of ring chromosomes which consistently harbor sequences derived from chromosomes 17 and 22. Second, the identification of this new chromosome marker, and eventually of the underlying molecular rearrangement, should help to classify DP, a soft-tissue tumor of still uncertain cell origin. In addition, it could be used to differentiate DP from truly benign or malignant entities, in order that this tumor of intermediate malignancy could be adequately managed.
187 citations
TL;DR: Comparative chromosome painting with individual human chromosome-specific libraries (CSLs) on cattle metaphase chromosomes delineated 46 homologous chromosomal segments between the two species and strongly supports the detected gross homologies between the karyotypes of the twospecies.
Abstract: Comparative chromosome painting with individual human chromosome-specific libraries (CSLs) on cattle metaphase chromosomes delineated 46 homologous chromosomal segments between the two species. Continuous arrangement of these segments on individual cattle chromosomes demonstrates a nearly complete coverage of the bovine karyotype and shows physical boundaries of bovine chromosomal segments homologous to individual human chromosomes. Alignment of the available comparative gene mapping data with the homologous segments strongly supports the detected gross homologies between the karyotypes of the two species. In addition to cattle, four human CSLs were hybridized to sheep metaphase chromosomes also, to further verify the known karyotype homology within the Bovidae. Besides its application to karyotype evolution research, the comparative knowledge provides for rapid expansion of the much needed Type I locus-based bovine gene map.
180 citations
TL;DR: Results indicate that some morphological abnormalities in the sperm heads are associated with their chromosome defects, and this is similar to those found in previous studies using the hamster oocyte-human sperm fusion system.
Abstract: The chromosome constitution of human spermatozoa was determined after injecting individual spermatozoa into mouse oocytes. Of a total 279 eggs arrested at first cleavage metaphase, 200 (71.7%) were suitable for the analysis of sperm chromosomes. Incidences of spermatozoa with numerical and structural chromosome aberrations were 1.3 and 6.9% respectively in spermatozoa with normal head morphology, showing values comparable with those found in previous studies using the hamster oocyte-human sperm fusion system. The ratio of X- to Y-bearing spermatozoa did not differ significantly from the expected 1:1 ratio. The incidence of structural chromosome aberrations was about four times higher in spermatozoa with amorphous, round and elongated heads (26.1%) than in those with morphologically normal heads, whereas the incidence of aneuploidy was not significantly different between the two groups. No increase in chromosome aberrations was found in spermatozoa with large heads. The same was true for spermatozoa with small heads. Although the sample size used in this study is rather small, the results nevertheless indicate that some morphological abnormalities in the sperm heads are associated with their chromosome defects.
TL;DR: A map demarcating physical boundaries of human homologies on individual pig chromosomes is complemented with a detail survey of the physical and genetic linkage mapping data in the two species to provide a comprehensive and updated comparative status of the human and porcine genomes.
Abstract: ZOO-FISH with chromosome-specific DNA libraries (CSLs) from individual flow-sorted human chromosomes was applied on porcine metaphase chromosomes to establish segment homology between the pig and human karyotypes. Forty-seven porcine chromosomal segments corresponding to all human chromosomes except the Y were delineated, resulting in a nearly complete coverage of the porcine karyotype. The syntenic segments detected were further confirmed by the gene mapping information available in the two species. A map demarcating physical boundaries of human homologies on individual pig chromosomes is complemented with a detail survey of the physical and genetic linkage mapping data in the two species. The resultant map, thus, provides a comprehensive and updated comparative status of the human and porcine genomes.
TL;DR: A single critical region of 2-3 Mb in size is identified in which 11q14-923 aberrations in LPD cluster are identified, providing the basis for the identification of the gene(s) at 11q22.3- 923.1 that are involved in the pathogenesis of LPD.
Abstract: Aberrations of the long arm of chromosome 11 are among the most common chromosome abnormalities in lymphoproliferative disorders (LPD). Translocations involving BCL1 at 11q13 are strongly associated with mantle cell lymphoma. other nonrandom aberrations, especially deletions and, less frequently, translocations, involving bands 11q21-923 have been identified by chromosome banding analysis. To date, the critical genomic segment and candidate genes involved in these deletions have not been identified. In the present study, we have analyzed tumors from 43 patients with LPD (B-cell chronic lymphocytic leukemia, n = 40; mantle cell lymphoma, n = 3) showing aberrations of bands 11q21-923 by fluorescence in situ hybridization. As probes we used Alu-PCR products from 17 yeast artificial chromosome clones spanning chromosome bands 11q14.3-923.3, including a panel of yeast artificial chromosome clones recognizing a contiguous genomic DNA fragment of approximately 9-10 Mb in bands 11q22.3-923.3. In the 41 tumors exhibiting deletions, we identified a commonly deleted segment in band 11q22.3-923.1; this region is approximately 2-3 Mb in size and contains the genes coding for ATM (ataxia telangiectasia mutated), RDX (radixin), and FDX1 (ferredoxin 1). Furthermore, two translocation break-points were localized to a 1.8-Mb genomic fragment contained within the commonly deleted segment. Thus, we have identified a single critical region of 2-3 Mb in size in which 11q14-923 aberrations in LPD cluster. This provides the basis for the identification of the gene(s) at 11q22.3-923.1 that are involved in the pathogenesis of LPD.
TL;DR: Double FISH experiments demonstrated that the 5S rDNA which is not sex linked is located at the NOR bearing arm close to the major ribosomal RNA genes, similar to the situation observed in Atlantic salmon.
Abstract: The karyotype of the rainbow trout is characterized by a primitive XX/XY sex-determining chromosomal system. (Thorgaard et al., 1977). In the present study using FISH we have physically linked the 5S rRNA genes to the partially undifferentiated X chromosome pair. PCR amplified 5S rDNA was used for FISH and hybridization signals indicated that the genes were duplicated, present in one acrocentric and one metacentric pair of chromosomes. After analyzing several individuals, the female metaphases showed four fluorescent signals whereas males presented only three signals. Two of the three signals obtained in males corresponded to the metacentric pair whereas the single signal was mapped to the heterochromatin that cytologically differentiates the X chromosome from the Y chromosome. Double FISH experiments demonstrated that the 5S rDNA which is not sex linked is located at the NOR bearing arm close to the major ribosomal RNA genes (5.8S, 18S and 28S), similar to the situation observed in Atlantic salmon (Pendas et al., 1994a).
Journal Article•
TL;DR: The results corroborate the pooled data obtained from human sperm karyotypes and suggest that the sex chromosome bivalent and the chromosome 21 bivalent are more susceptible to nondisjunction during spermatogenesis.
Abstract: While it is known that all chromosomes are susceptible to meiotic nondisjunction, it is not clear whether all chromosomes display the same frequency of nondisjunction. By use of multicolor FISH and chromosome-specific probes, the frequency of disomy in human sperm was determined for chromosomes 1, 2, 4, 9, 12, 15, 16, 18, 20, and 21, and the sex chromosomes. A minimum of 10,000 sperm nuclei were scored from each of five healthy, chromosomally normal donors for every chromosome studied, giving a total of 418,931 sperm nuclei. The mean frequencies of disomy obtained were 0.09% for chromosome 1; 0.08% for chromosome 2; 0.11% for chromosome 4; 0.14% for chromosome 9; 0.16% for chromosome 12; 0.11% for chromosomes 15, 16, and 18; 0.12% for chromosome 20; 0.29% for chromosome 21; and 0.43% for the sex chromosomes. Data for chromosomes 1, 12, 15, and 18, and the sex chromosomes have been published elsewhere. When the mean frequencies of disomy were compared, the sex chromosomes and chromosome 21 had significantly higher frequencies of disomy than that of any other autosome studied. These results corroborate the pooled data obtained from human sperm karyotypes and suggest that the sex chromosome bivalent and the chromosome 21 bivalent are more susceptible to nondisjunction during spermatogenesis. From these findings, theories proposed to explain the variable incidence of nondisjunction can be supported or discarded as improbable.
TL;DR: The genetic events leading to genesis of testicular germ cell tumors in men appear to be related to aneuploidization followed by the formation of an i(12p) isochromosome, the latter characterizing the preponderant number oftesticular germcell tumors.
TL;DR: The need for the introduction of molecular techniques such as chromosome painting and physical mapping of genetic markers for the identification of small acrocentrics is discussed.
Abstract: Karyotyping of dog chromosomes is a difficult task owing to the high diploid number of chromosomes (2n=78) and the similar morphology of autosomes, all of which are acrocentrics. In this report 22 of the 39 G-banded chromosome pairs and their corresponding ideograms have been standardized. The ideogram comprises altogether 235 bands. The need for the introduction of molecular techniques such as chromosome painting and physical mapping of genetic markers for the identification of small acrocentrics is discussed.
TL;DR: Multicolor FISH analysis permits an accurate distinction between disomic and diploid sperm and allows analysis of large sample sizes, and may be useful for future studies of potential environmental and occupational mutagens.
Abstract: Aneuploidy and diploidy frequencies for chromosomes 1, 12, X, and Y were assessed in 225,846 sperm from 10 normal men. Results from 5 of the men have previously been reported. Multicolor fluorescence in situ hybridization (FISH) was used to control for lack of probe hybridization and to distinguish diploidy from disomy. A minimum of 10,000 sperm per donor were evaluated for each chromosome. Sperm were considered disomic if two fluorescent signals were separated by a distance of a minimum of one signal domain. The mean frequencies of disomic sperm for chromosomes 1 and 12 were 0.11% (range 0.05-0.18%) and 0.16% (range 0.10-0.25%), respectively. The means for the sex chromosomal aneuploidies were 0.07% XX, 0.18% YY, and 0.16% XY, totaling 0.42% for all sex chromosomes (range 0.23-0.71%). The incidence of disomic sperm for the sex chromosomes was significantly increased compared to the frequency for the autosomes, corroborating results obtained from studies of sperm karyotypes and spontaneous abortions. The mean frequencies of single X- and Y-bearing sperm were 50.1% and 49.0%, respectively--not significantly different from 50%. The mean frequency of diploid sperm was 0.16% (0.06-0.42%). Interdonor heterogeneity was found to exist for disomy 1, XX, YY, and diploidy, suggesting significant variation among normal men. Comparison of these FISH results to our historical sperm karyotypes demonstrated that the sex ratios and disomy frequencies for chromosomes 1 and X were similar. However, there was a significantly increased frequency of disomic sperm for chromosomes 12, YY, and XY in FISH data compared with sperm karyotypes. In general, FISH data agreed quite well with values from sperm karyotyping, including the increased frequency of sex chromosomal aneuploidy compared with autosomal aneuploidy in sperm. Multicolor FISH analysis permits an accurate distinction between disomic and diploid sperm and allows analysis of large sample sizes. This powerful technology may be useful for future studies of potential environmental and occupational mutagens.
TL;DR: It is concluded that trisomy 3 occurs in a high proportion of extranodal, nodal and splenic MZBCL and FISH on interphase nuclei is an additional and sensitive tool in detecting an increased copy number of chromosome 3 in MZ BCL.
Abstract: Trisomy 3 represents the most frequent and consistent chromosomal abnormality characterizing the recently defined entity marginal zone B-cell lymphoma (MZBCL). By cytogenetic analysis and/or fluorescence in situ hybridization (FISH) on interphase nuclei we found an increased copy number of chromosome 3 in 22/36 (61%) successfully analysed cases, including 8/12 cases with extranodal MZBCL, 8/13 cases with nodal MZBCL, and 6/11 patients with splenic MZBCL. Sensitivity of interphase cytogenetics was somewhat higher than that of conventional cytogenetic investigation, Structural chromosomal changes involving at least one chromosome 3 were seen in 11/20 cases with an increased copy number of chromosome 3: +del(3)(p13) was demonstrated in three cases, and was the sole chromosomal abnormality in one of them: +i(3)(q10) was seen in two other patients; and rearrangements involving various breakpoints on the long arm of chromosome 3 were found in the remaining cases, FISH on metaphase spreads confirmed these structural abnormalities and additionally showed two unexpected translocations involving chromosome 3, We conclude that: (1) trisomy 3 occurs in a high proportion of extranodal, nodal and splenic MZBCL; (2) FISH on interphase nuclei is an additional and sensitive tool in detecting an increased copy number of chromosome 3 in MZBCL; (3) additional structural abnormalities involving the long arm of chromosome 3 are frequent but non-recurrent and are perhaps secondary changes; and (4) abnormalities such as +del(3)(p13) and +i(3)(q10) suggest that genes located on the long arm of chromosome 3 are of particular importance in the pathogenesis of MZBCL.
TL;DR: In this article, a method was proposed to determine aneuploidy for chromosome 16 by recycling nuclei of cells already analyzed for chromosomes X,Y, 18, 13, and 21 using multiple-probe fluorescence in situ hybridization in preimplantation human embryos.
TL;DR: Previous findings by performing FISH using chromosome 19 paint and microFISH probes and patient samples with and without abnormalities of chromosome 19 identified by G-banding were extended, finding amplification and overexpression of the AKT2 putative oncogene but not the ERCC-2 DNA repair gene in this chromosomal region may contribute to ovarian carcinoma pathogenesis or progression.
TL;DR: This constitutes the first report of the production of karyotypically stable partial hybrids involving highly unrelated species from two subfamilies of the Gramineae and the subsequent recovery of fertile oat-maize chromosome addition lines.
Abstract: In cereals, interspecific and intergeneric hybridizations (wide crosses) which yield karyotypically stable hybrid plants have been used as starting points to widen the genetic base of a crop and to construct stocks for genetic analysis. Also, uniparental genome elimination in karyotypically unstable hybrids has been utilized for cereal haploid production. We have crossed hexaploid oat (2n=6x=42, Avena sativa L.) and maize (2n=2x=20, Zea mays L.) and recovered 90 progenies through embryo rescue. Fifty-two plants (58%) produced from oat x maize hybridization were oat haploids (2n=3x=21) iollowing maize chromosome elimination. Twenty-eight plants (31%) were found to be stable partial hybrids with 1-4 maize chromosomes in addition to a haploid set of 21 oat chromosomes (2n=21+1 to 2n=21+4). Ten of the ninety plants produced were found to be apparent chromosomal chimeras, where some tissues in a given plant contained maize chromosomes while other tissues did not, or else different tissues contained a different number of maize chromosomes. DNA restriction fragment length polymorphisms (RFLPs) were used to identify the maize chromosome(s) present in the various oat-maize progenies. Maize chromosomes 2, 3, 4, 5, 6, 7, 8, and 9 were detected in partial hybrids and chromosomal chimeras. Maize chromosomes 1 and 10 were not detected in the plants analyzed to-date. Furthermore, partial self-fertility, which is common in oat haploids, was also observed in some oat-maize hybrids. Upon selfing, partial hybrids with one or two maize chromosomes showed nearly complete transmission of the maize chromosome to give self-fertile maize-chromosome-addition oat plants. Fertile lines were recovered that contained an added maize chromosome or chromosome pair representing six of the ten maize chromosomes. Four independently derived disomic maize chromosome addition lines contained chromosome 4, one line carried chromosome 7, two lines had chromosome 9, one had chromosome 2, and one had chromosome 3. One maize chromosome-8 monosomic addition line was also identified. We also identified a double disomic addition line containing both maize chromosomes 4 and 7. This constitutes the first report of the production of karyotypically stable partial hybrids involving highly unrelated species from two subfamilies of the Gramineae (Pooideae - oat, and Panicoideae - maize) and the subsequent recovery of fertile oat-maize chromosome addition lines. These represent novel material for gene/marker mapping, maize chromosome manipulation, the study of maize gene expression in oat, and the transfer of maize DNA, genes, or active transposons to oat.
TL;DR: The data suggest that there is a gene in chromosome 22, probably a tumor suppressor, inactivation of which may be involved in the genesis of renal rhabdoid tumors, and a second gene in chromosomes segment 11p15.5, in the region of the putative WT2 gene, may also be involved.
Abstract: Rhabdoid tumors of the kidney are highly malignant neoplasms that occur primarily within the first 3 years of life. Although they are regarded as distinct from Wilms' tumors, their pathogenesis remains unclear. Whereas most cytogenetic studies of these tumors have revealed normal karyotypes, a few reports have indicated abnormalities at chromosome regions 22q and 11p15.5. We analyzed 30 primary renal rhabdoid tumors for loss of heterozygosity (LOH) at both regions and found that 24 of 30 tumors (80%) had LOH at chromosome arm 22q and that 5 of 30 (17%) had LOH at chromosome band 11p15.5. All of the five tumors with LOH at chromosome arm 11p also had LOH at chromosome arm 22q. The data suggest that there is a gene in chromosome 22, probably a tumor suppressor, inactivation of which may be involved in the genesis of renal rhabdoid tumors. A second gene in chromosome segment 11p15.5, in the region of the putative WT2 gene, may also be involved, in at least a subset of rhabdoid tumors. In addition, five tumors were characterized by microsatellite instability at three or more of 21 loci examined, suggesting a possible role for a replicative error in tumorigenesis or progression in some cases of renal rhabdoid tumors. Genes Chromosom Cancer 15:10-17 (1996).
TL;DR: The amplification of a restricted region of 12p in primary TGCT confirms and extends previous observations and represents an important step forward in the identification of gene(s) on 12p relevant for the pathogenesis of these tumors.
TL;DR: Investigation of patients with Philadelphia (Ph) chromosome positive acute lymphoblastic leukaemia found that additional chromosome aberrations may characterize distinct subgroups of Ph‐positive ALL, and the necessity of the complementing use of chromosome banding analyses, polymerase chain reaction (PCR) assays, and fluorescence in situ hybridizations in the accurate identification of Ph-positive patients has become evident.
Abstract: The clinical and biological significance of additional chromosome aberrations was investigated in a large series of 66 adult patients with Philadelphia (Ph) chromosome positive acute lymphoblastic leukaemia (ALL). Additional chromosome changes were observed in 71% of the cases. 9p abnormalities were identified in 26%, and monosomy 7 as well as hyperdiploid karyotypes >50 were both found in 17% of cases. 9p anomalies were characterized by a low complete remission (CR) rate (58%) and an extremely short median remission duration (MRD; 100 d). In patients with monosomy 7, the poor treatment outcome was confirmed (CR rate 55%; MRD 113 d). In contrast, all patients with hyperdiploid karyotypes >50 achieved CR, and the overall survival was superior to all other Ph-positive ALL patients except those without additional chromosome aberrations. Exclusive rearrangement of the minor breakpoint cluster region of the BCR gene and lack of coexpression of myeloid-associated antigens in cases with 9p anomalies as well as a high frequency of rearrangements of the major breakpoint cluster region of the BCR gene in patients with monosomy 7 (89%) further substantiated that additional chromosome aberrations may characterize distinct subgroups of Ph-positive ALL. Moreover, the necessity of the complementing use of chromosome banding analyses, polymerase chain reaction (PCR) assays, and fluorescence in situ hybridizations in the accurate identification of Ph-positive patients has become evident due to variant Ph translocations in 3%, and negative PCR assays in 4% of the cases.
TL;DR: The study suggested a correlation between the percentage of abnormal cells and an abnormal phenotype, and for mosaicism involving a terminal deletion, the possibility of a familial fragile site should be considered.
Abstract: Among 179,663 prenatal diagnosis cases collected from ten institutions and two publications, 555 (0.3 per cent) were diagnosed as having chromosome mosaicism. Of these, 57 (10.3 per cent) were mosaic for an autosomal structural abnormality, 28 (5 per cent) for a sex chromosome structural abnormality, and 85 (15.3 per cent) were mosaic for a marker chromosome. Ninety-five cases of prenatally diagnosed mosaicism with a structural abnormality in an autosome and a normal cell line, and with a known phenotypic outcome, were collected for karyotype-phenotype correlations through our collaboration (40 cases), a prior survey (26 cases), and published reports (29 cases). They included 13 balanced reciprocal translocations, one unbalanced reciprocal translocation, four balanced Robertsonian translocations, four unbalanced Robertsonian translocations, four inversions, 17 deletions, three ring chromosomes, 19 i(20q), seven +i(12p), six other isochromosomes, and 17 partial trisomies resulting from a duplication or other rearrangement. All cases mosaic for a balanced structural rearrangement resulted in a normal phenotype. All cases of 46/46,i(20q) resulted in normal liveborns. Five of seven cases with 46/47,+i(12p) had an abnormal phenotype compatible with Killian-Pallister syndrome. The overall risk for an abnormal outcome for a mosaic case with an unbalanced structural abnormality, excluding 46/46,i(20q) and 46/47,+i(12p), is 40.4 per cent. In the same category, the study also suggested a correlation between the percentage of abnormal cells and an abnormal phenotype. For mosaicism involving a terminal deletion, the possibility of a familial fragile site should be considered.
TL;DR: The independent origin of at least three evolutionary lines leading to the cultivated taxa of Capsicum is supported, and the fluorochrome bands generally (but not completely) correspond to the Giemsa C-bands.
Abstract: Fluorochrome chromosome banding is applied for the first time to 15 samples of five cultivatedCapsicum species, all with 2n = 24, and allows a detailed analysis of the karyotypes (Tables 2–3, Fig. 8). Banding patterns differ between cytotypes, species and groups, reflecting the dynamics of chromosomal differentiation and evolutionary divergence. Taxa have from 1 to 4 NOR-bearing satellited chromosome pairs and exhibit increasing numbers of terminal (rarely intercalary and indistinct centromeric) heterochromatic fluorescent bands. Amounts of heterochromatin (expressed in % of karyotype length) increase from the group withC. annuum (1.80–2.88),C. chinense (3.91–5.52), andC. frutescens (5.55) toC. baccatum (7.30–7.56), and finally toC. pubescens (18.95). In all taxa CMA+DAPI—(GC-rich) constitutive heterochromatin dominates, onlyC. pubescens has an additional CMAo DAPI+ (AT-rich) band. The fluorochrome bands generally (but not completely) correspond to the Giemsa C-bands. Structural heterozygosity can be demonstrated but is not prominent. The independent origin of at least three evolutionary lines leading to the cultivated taxa ofCapsicum is supported.
TL;DR: 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.
Abstract: Using peripheral blood lymphocyte cultures and dual-laser 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.
TL;DR: The present study concludes that tumors and tumor cell lines from patients with CC demonstrate significant genomic, but not microsatellite length, instability, and examines the CC gene(s) on chromosome 2p16, which appears to be involved in the regulation of genomic stability of dividing cells, in particular the structure of telomeres in replicating chromosomes and the function of the mitotic apparatus.
Abstract: Carney complex (CC) is a familial multiple neoplasia and lentiginosis syndrome, transmitted in an autosomal dominant manner. It is the only familial form of cardiac and skin myxomas known and includes endocrine neoplasms causing Cushing's syndrome [primary pigmented nodular adrenocortical disease (PPNAD)] and acromegaly (GH-producing adenoma). The molecular defect leading to CC remains unknown, but was recently mapped to chromosome 2p16 by linkage analysis. This region has exhibited cytogenetic aberrations in atrial myxomas from patients with CC and harbors the hMSH2 and hMSH6 genes, which are involved in the preservation of microsatellite length stability of replicating human cells. In the present study, we examined 15 tumor and normal tissue specimens from 13 patients with CC [GH-producing adenoma (n = 1), adrenal tumors (PPNAD, n = 8), thyroid cancer (n = 1), normal adrenal gland (n = 1)] and 4 cultured cell lines [heart myxoma (n = 3) and eyelid myxoma (n = 1)]. Chromosome analysis was obtained by standard cytogenetic techniques. One of the myxoma cell lines and 3 PPNAD specimens contained multiple telomeric associations (tas). The normal adrenocortical tissue from a patient with PPNAD contained no apparent chromosomal anomalies, whereas the neighboring PPNAD tissue demonstrated tas. DNA was extracted from peripheral blood, tumor cell lines, and frozen or paraffin-embedded tissues and subjected to PCR amplification with primers from 64 microsatellite locations covering chromosomes 1 and 3-22 and 14 loci covering chromosome 2. The alterations detected were loss and gain of heterozygosity (LOH and GOH; 49% and 26%, respectively), deletions of both alleles (DEL; 10%), and microsatellite length instability (15%). GOH and LOH were the most frequent changes, with telomeric markers significantly over-represented (P 0.1). We conclude that tumors and tumor cell lines from patients with CC demonstrate significant genomic, but not microsatellite length, instability. Thus, the CC gene(s) on chromosome 2p16 is different from the hMSH2 and hMSH6 genes and has dominant, rather than recessive, tumorigenic function. This gene(s) appears to be involved in the regulation of genomic stability of dividing cells, in particular the structure of telomeres in replicating chromosomes and/or the function of the mitotic apparatus.
TL;DR: Analysis of chromosomes of a wide variety of strains of Magnaporthe grisea using pulsed-field gel electrophoresis (PFGE), in combination with Southern hybridization and genetic crosses, concludes that many small M.grisea chromosomes are like B-chromosomes found in plants and animals.
Abstract: We have analyzed the chromosomes of a wide variety of strains of Magnaporthe grisea using pulsed-field gel electrophoresis (PFGE), in combination with Southern hybridization and genetic crosses. Strains analyzed included rice pathogens, field pathogens of grasses other than rice, and fertile laboratory strains. All M. grisea strains examined contain chromosomes in the size range from 2,000 kilobases (kb) to greater than 10,000 kb. Some strains also contain chromosomes, termed "mini-chromosomes," that range in size from 500 to 2,000 kb. Variation in chromosome numbers seems to be mainly among the minichromosomes. Infertile field isolates, including most rice pathogens, have a relatively high number of chromosome length polymorphisms. In contrast, some M. grisea strains from diverse hosts around the world are interfertile and have a relatively uniform karyotype, although translocations are present even among these fertile strains. There appears to be a correlation between the presence of minichromosomes and low levels of sexual fertility, although it is not yet clear if mini-chromosomes are a result or a cause of the low fertility. A mini-chromosome from a Chinese rice pathogen failed to segregate in crosses and it contained at least one DNA sequence that was found in mini-chromosomes of diverse strains, but not found in the larger standard chromosomes from these strains. These mini-chromosomes appear to be nonessential for growth and pathogenicity. Thus, we conclude that many small M. grisea chromosomes are like B-chromosomes found in plants and animals. However, size alone does not predict whether a small chromosome has B-chromosome-like properties. This is demonstrated by the normal Mendelian segregation of a small chromosome present in one parental strain used in an M. grisea RFLP mapping project that was apparently formed through an unequal translocation between two larger chromosomes.