<p>This study was designed to evaluate the frequency of aneuploid sperm in young adult mice of the genotype (102/E1 x C3H/E1)F1 determined by the fluorescence in situ hybridization (FISH) procedure and to evaluate the frequencies of aneuploid sperm observed by FISH compared with the frequencies of aneuploid offspring. Three-chromosome FISH was applied to determine the fractions of hyperhaploid and diploid sperm with DNA probes specific for chromosomes X, Y and 8. The animals were treated with three common solvents. Sperm smears were prepared for FISH by two similar protocols and were scored by different persons and in two different laboratories. There were no significant differences between scorers or laboratories. The frequencies of the sex chromosome aneuploidies in sperm (Y-Y and X-Y) were compared to the frequencies of mice carrying sex chromosome aneuploidy among controls of the heritable translocation assay in studies conducted from 1975-1995. To identify aneuploid individuals, untreated males and females of the genotype (102/E1 x C3H/E1)F1 were mated to assess their fertility by observing three consecutive litters. Semisterile and sterile animals were further analysed by meiotic cytogenetics and by karyotyping to determine the incidence of reciprocal translocations and sex chromosome aneuploidies (XXY and XYY). Based on the analysis of 175247 sperm and 9840 progeny, the frequency of Y-Y sperm was 0.01% while 0.03% of the offspring were XYY. The frequency of X-Y sperm was 0.005% while 0.02% of the offspring were XXY. The frequencies of aneuploid sex chromosomes were not significantly different between sperm and offspring. This allows two conclusions. First, there was no detectable prenatal selection against these sex-chromosomal aneuploid offspring, and second, germ cell aneuploidy can be reliably determined in mice by sperm FISH analyses.</p>

The French-American-British subtype acute myelomonocytic leukemia with abnormal eosinophils (FAB AML M4Eo) with pericentric inversion of chromosome 16 is cytomorphologically defined by a myelomonoblastic blast population and abnormal eosinophils. Until now, it remained an open question whether these abnormal eosinophils are part of the malignant clone or an epiphenomenon. We analyzed five cases of AML M4Eo with inv(16) and combined May-Grünwald-Giemsa staining with fluorescence in situ hybridization using yeast artificial chromosome clone 854E2, which spans the inv(16) breakpoint on 16p. In the case of inv(16), three instead of the normal two hybridization signals can be observed both on metaphase spreads and in interphase cells. With this approach, we were able to show inversion 16 in abnormal eosinophils and, therefore, identified them as a part of the leukemic cell population.

The molecular basis of malignant mesothelioma is poorly known. We examined genetic changes in 11 mesothelioma specimens by comparative genomic hybridization (CGH). Five DNA specimens originated from uncultured tumor tissues and six from cell lines established from the same patients. Findings from the classical karyotypic characterization of both primary tumors and cell lines have been reported previously. In the CGH analyses the most common genetic alterations in the 11 mesothelioma specimens were losses of chromosomal regions in 1p, 8p, 14q, and 22q and gains of 5p, 6p, 8q, 15q, 17q, and 20. The cell lines had on average a much higher total number of genetic changes than the uncultured tumor specimens. Clonal relationship between the cell lines and the uncultured tissue specimens could not usually be demonstrated even though they originated from the same patient. The observed differences may partly be due to high frequency of chromosomal rearrangements, which CGH cannot detect, partly due to contamination of tumor specimens with normal tissue, and partly due to genetic evolution in tumor cell lines.

We studied DNA copy number changes in diffuse large B-cell lymphoma using comparative genomic hybridization analysis on 20 primary tumors and on 12 recurrent tumors excised after chemotherapy or radiotherapy. Twenty-nine (91%) of the cases showed abnormal copy number karyotypes. Chromosomal regions at X (41%), 1q (38%), 7 (31%), 3 (24%), 6p (21%), 11 (21%), 12 (21%), and 18 (21%) were most frequently gained, and the most common losses involved 6q (38%), X (21%), 1p (14%), and 8p (10%). High-level amplifications were observed at 6p23-ter, 10p12-14, 17p1l.2, 18q21-ter, and Xq22-ter, all but 18q appearing only in the recurrent tumors. Gains (median, 2; range, 0 to 10) were more frequent than losses (median, 1; range, 0 to 7; P = .0004). The median number of aberrations found in the recurrent tumors (6.5) was greater than that in the primary tumors (2; P = .01). The copy number changes found in the recurrent tumors were more random than those found in the primary tumors, which were mainly located in the most frequently affected regions. Our findings are in line with those observed using conventional cytogenetic analysis, but especially novel high-level amplifications were detected. Southern blot analysis showed BCL2 amplification, but not translocation t(14;18)(q32;q21), in cases in which a gain at 18q was detected by comparative genomic hybridization, which strongly suggests that, in addition to translocation, gene amplification is another mechanism for the overexpression of the BCL2 protein.

Our aim was to identify chromosomal regions that are likely to harbor previously unknown genes with an important role in the genesis of osteosarcoma. Comparative genomic hybridization was used to screen for losses and gains of DNA sequences along all chromosome arms in 11 tumors. Extensive genetic aberrations, with an average of 11 changes/tumor (range, 1-20), were found in 10 of the 11 specimens. High level amplifications of small chromosomal regions were detected in eight tumors. These involved the 12q12-q13 region (known to contain the SAS-MDM2 locus) and several previously unreported amplification sites such as 17p11-p12, 3q26, and Xq12. When all DNA sequence gains were evaluated, the gains at 8q and Xp were most common (45%). The most common losses of DNA sequences were seen at 2q, 6q, 8p, and 10p (36%). In conclusion, despite the very complex pattern of genetic changes in osteosarcomas, certain chromosomal regions appear to be affected more often than others. Most of these regions have not previously been reported to be implicated in osteosarcomas and may thus highlight locations of novel genes with an important role in the development and progression of these tumors.

<p>The French-American-British subtype acute myelomonocytic leukemia with abnormal eosinophils (FAB AML M4Eo) with pericentric inversion of chromosome 16 is cytomorphologically defined by a myelomonoblastic blast population and abnormal eosinophils. Until now, it remained an open question whether these abnormal eosinophils are part of the malignant clone or an epiphenomenon. We analyzed five cases of AML M4Eo with inv(16) and combined May-Grünwald-Giemsa staining with fluorescence in situ hybridization using yeast artificial chromosome clone 854E2, which spans the inv(16) breakpoint on 16p. In the case of inv(16), three instead of the normal two hybridization signals can be observed both on metaphase spreads and in interphase cells. With this approach, we were able to show inversion 16 in abnormal eosinophils and, therefore, identified them as a part of the leukemic cell population.</p>