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PubMed1990

Mapping of insertion element IS5 in the Escherichia coli K-12 chromosome. Chromosomal rearrangements mediated by IS5.

We identified phage clones containing insertion element IS5 in a set of 476 lambda phage clones carrying chromosomal segments that cover almost the entire chromosome of Escherichia coli K-12 W3110. Precise locations and orientations of IS5 were then determined by cleavage analysis of phage DNAs containing them. We mapped 23 copies of IS5 (named is5A to is5W) on the W3110 chromosome. Among them, ten were identified as the common elements present at the same locations in both chromosomes of W3110 and another E. coli K-12 strain, JE5519. While most of the mapped IS5 elements were scattered over the W3110 chromosome, four copies of IS5 (designated is5L, is5M, is5N and is5O) were in a region representing tandem duplication of a DNA segment flanked by two copies of IS5. Interestingly, one unit of this DNA segment as well as a portion of it was seen also in a tandem array in a different region where two copies of IS5 (designated is5P and is5Q) were present. In particular two pairs of the mapped IS5 elements may have been involved in inversion of the chromosomal segments in two of the E. coli K-12 derivatives.

Bacteriophage lambda↗

PubMed1985

Cloning the chromosomal breakpoint of t(14;18) human lymphomas: clustering around JH on chromosome 14 and near a transcriptional unit on 18.

Specific chromosomal translocations found in distinct neoplasms suggest that genes that flank such breakpoints play a critical role in transformation. We have characterized the t(14;18)(q32;q21) chromosomal translocation present in over 60% of human follicular lymphomas. We exploited an unexpected rearrangement of an Ig heavy-chain gene to clone the chromosomal breakpoint. An element isolated from 18q21 mediated translocations in all four t(14;18) bearing cell lines and in six of 11 follicular lymphomas, but did not normally rearrange in other B or non-B cells. The breakpoints clustered within a small 4.3 kb region on chromosome 18. The breakpoints on chromosome 14 were focused within or immediately 5' to JH. These breakpoints retained the Ig enhancer region close to a new transcriptional unit identified on chromosome segment 18q21. Since none of the cellular oncogenes are known to map to 18q21, cloning this element provides an opportunity to characterize a potentially new transforming gene.

Cell Line↗

PubMed2003

Translocation (12;21) followed by insertion of chromosome 3 material in the derivative chromosome 12 in a case of childhood acute lymphoblastic leukemia.

We report a 2-year-old boy with B-cell acute lymphoblastic leukemia. Cytogenetic studies at diagnosis with R-banding showed a 46,XY,ins(12;3)(p13;q?21q?22)/46,XY karyotype. Fluorescence in situ hybridization with TEL/AML1 probes and chromosome paints revealed complex rearrangements. The TEL/AML1 fusion gene was located on the derivative chromosome 21 but a segment of the long arm of a chromosome 3 was inserted between the proximal part of the short arm of the derivative chromosome 12 and the reciprocal part of the AML1 gene. This is consistent with an insertion of chromosome 3 into chromosome 12 after the t(12;21) took place, therefore indicating a probable secondary event due to clonal evolution.

Child, Preschool↗

PubMed1999

Identification of a ring chromosome in a myxoid malignant fibrous histiocytoma with chromosome microdissection and fluorescence in situ hybridization.

We investigated the origin of a ring chromosome in a myxoid malignant fibrous histiocytoma (MFH) by microdissection and fluorescence in situ hybridization (FISH) analyses. Cytogenetically, only two ring chromosomes were observed; the smaller ring was seen more frequently. The latter was microdissected, and the material used for FISH. Hybridization of the microdissected labeled DNA to normal metaphase cells revealed that the signal localized only to 20q. Three signals were seen in the tumor cells using either the microdissected 20q probe or chromosome 20 centromeric probe, indicating the involvement of both the long arm and the centromere in the ring chromosome. The short arm of chromosome 20 did not appear to be involved in the formation of the ring chromosome.

Adult↗

PubMed1972

Chromosome 16: a specific chromosomal pathway for the origin of human malignancy?

Minkler, Gofman and Tandy (1970a, b) have recently reported data on the karyotype constitutions of human tissue culture cell lines and human tumours, as gathered by a semi-automatic chromosome analysis system. The data appears to show a relationship between the relative number of "number 16" chromosomes and malignancy. We have tested the ability of the "cutting line" approach they used to correctly classify chromosomes from a sample of 723 cells from 100 normal subjects. The cutting line scheme gave very different results from those of an experienced cytogeneticist. The method also failed to give correct average numbers of chromosomes per class. We are thus led to question the conclusions reached by Minkler et al. It appears possible that their relatively consistent finding of an excess of "number 16" chromosomes in their largely hyperploid material may be an artefact of their classification scheme, arising from measurement normalization problems, rather than a reflection of a real excess of "number 16" or even of "number 16-like" chromosomes.

Cell Line↗

PubMed2002

A comparative map of chicken chromosome 24 and human chromosome 11.

To improve the physical and comparative map of chicken chromosome 24 (GGA24; former linkage group E49C20W21) bacterial artificial chromosome (BAC) contigs were constructed around loci previously mapped on this chromosome by linkage analysis. The BAC clones were used for both sample sequencing and BAC end sequencing. Sequence tagged site (STS) markers derived from the BAC end sequences were used for chromosome walking. In total 191 BAC clones were isolated, covering almost 30% of GGA24, and 76 STS were developed (65 STS derived from BAC end sequences and 11 STS derived within genes). The partial sequences of the chicken BAC clones were compared with sequences present in the EMBL/GenBank databases, and revealed matches to 19 genes, expressed sequence tags (ESTs) and genomic clones located on human chromosome 11q22-q24 and mouse chromosome 9. Furthermore, 11 chicken orthologues of human genes located on HSA11q22-q24 were directly mapped within BAC contigs of GGA24. These results provide a better alignment of GGA24 with the corresponding regions in human and mouse and identify several intrachromosomal rearrangements between chicken and mammals.

Animals↗

PubMed1999

Identification of the inverted chromosome 16 using chromosome painting.

The inverted chromosome 16 is commonly associated with acute myelomonocytic leukaemia (AML) M4 with bone marrow eosinophilia. Cytogenetic identification of the inverted chromosome 16 can be difficult. To help identify the inversion in bone marrow samples from patients referred for the diagnosis of AML-M4, we applied the molecular cytogenetic technique of chromosome painting using chromosome 16 p-arm paint. The results were concordant with standard chromosome analyses and clearly allowed for the identification of a pericentric inversion within chromosome 16 even in poor-quality metaphase spreads.

Chromosome Inversion↗

PubMed2002

A large dispersed chromosomal region required for chromosome segregation in sporulating cells of Bacillus subtilis.

The cis-acting sequences required for chromosome segregation are poorly understood in most organisms, including bacteria. Sporulating cells of Bacillus subtilis undergo an unusual asymmetric cell division during which the origin of DNA replication (oriC) region of the chromosome migrates to an extreme polar position. We have now characterized the sequences required for this migration. We show that the previously characterized soj-spo0J chromosome segregation system is not essential for chromosome movement to the cell pole, so this must be driven by an additional segregation mechanism. Observations on a large set of precisely engineered chromosomal inversions and translocations have identified a polar localization region (PLR), which lies approximately 150-300 kbp to the left of oriC. Surprisingly, oriC itself has no involvement in this chromosome segregation system. Dissection of the PLR showed that it has internal functional redundancy, reminiscent of the large diffuse centromeres of most eukaryotic cells.

Bacillus subtilis↗

PubMed1992

Gene targeting for somatic cell manipulation: rapid analysis of reduced chromosome hybrids by Alu-PCR fingerprinting and chromosome painting.

The techniques of reverse genetics rely heavily on parasexual methods for manipulating the human genome. However, the application of somatic cell genetics is severely limited by the availability of suitable endogenous selectable markers in the genome. We have addressed this problem by targeting a universally selectable marker into a predetermined region of the genome, using a stringent selection for homologous recombination. Correct gene targeting to human chromosome 7q11 was screened for by Southern blotting and confirmed by fluorescent in situ hybridization. Reduced chromosome 7 hybrids were generated by chromosome mediated gene transfer and selection for the neo gene. The resultant transgenomes were characterized by a combination of L1 fingerprinting, locus specific marker analysis, Alu-PCR and chromosome 'painting'. Alu-PCR and L1 'fingerprints' are complementary and mutually consistent. Chromosome 'painting' reflects and extends the results obtained for specific marker co-transfer. Thus Alu-PCR 'fingerprinting' and 'painting' combine to rapidly provide an accurate picture of transgenome content and complexity. Gene targeting, chromosome tagging and subsequent isolation can be applied to any region of the genome for which a molecular probe is available.

Animals↗

PubMedDate not supplied

A comparative approach to physical and linkage mapping of genes on canine chromosomes using gene-associated simple sequence repeat polymorphisms illustrated by studies of dog chromosome 9.

We describe and illustrate a comparative approach to creating physical and linkage maps of genes on dog chromosomes. The approach is particularly useful in species, like the dog, which have a rudimentary gene map not integrated with microsatellite loci. Human or mouse cDNAs for genes to be mapped are used to isolate cosmid or phage clones from dog genomic libraries. Clones verified to contain the homologous canine gene coding sequences are screened for "gene-associated" simple sequence repeat polymorphisms (SSRPs). The unique sequences flanking the repeats are used to design PCR primers to amplify the repeat and gene-associated SSR length differences that are informative for linkage analysis used in canine pedigrees to study linkage between loci or with diseases. The same canine clones are employed as probes in fluorescence in situ hybridization (FISH) studies to physically map the loci to specific sites on dog chromosomes. This approach creates a combined gene and gene-associated microsatellite anchor locus framework map. In this article we review our recent use of this approach to map a series of genes found on human chromosome 17 (HSA17) to two dog chromosomes. Canine chromosome 9 (CFA9) contains 11 loci found on HSA17q, while two genes from HSA17p map to CFA5, demonstrating disruption of HSA17 synteny at the centromere. The order of 11 HSA17q genes on CFA9 was conserved in the dog, but the entire group is inverted with respect to the centromere when compared to human and mouse. Maps created by this approach can be used to advantage for integrating anonymous microsatellites with gene maps, including microsatellites found in genome scans to be linked to canine diseases. This makes it possible to identify the homologous chromosomal region in the human or mouse genome and to make use of this information in formulating hypotheses regarding candidate genes, as has recently been illustrated by other investigators.

Animals↗

PubMed1989

Gene mapping on chorionic villi chromosomes by hybridization in situ: localization of cholinesterase cDNA binding sites to chromosomes 3q21, 3q26-ter and 16q21.

To adapt the in-situ hybridization approach for use in very early fetal development, comparative in-situ hybridization was initiated on chromosomes from chorionic villus sampling (CVS). An additional aim was to refine the localization of the chromosomal sites binding butyrylcholinesterase (BuChE) cDNA by mapping them in parallel to previously mapped genes of close locations. BuChEcDNA was previously found to bind to the long arms of lymphocyte chromosomes 3 and 16, with a wide distribution of grains suggesting two separate sites on chromosome 3. When labelled with 35S and hybridized with CVS chromosomes, BuChEcDNA was bound to three distinct sites, designated CHEL1, CHEL2 and CHEL3. These peaked at 3q21, 3q26-ter and 16q21 respectively. Parallel hybridization with the cDNA encoding transferrin receptor (TFRC) refined its localization to 3q29, in agreement with previously published results and in a distal position to CHEL2, whereas haptoglobin cDNA (HPcDNA) was correctly mapped at 16q24, distal to CHEL3. In view of the published genetic linkage between the CHEL1 locus and the transferrin TF gene on 3q25, this study suggests that one of the three sites carrying BuChE-coding sequences, namely CHEL2, harbours the functional CHEL1 gene. Thus, in-situ hybridization provides a rapid and precise method for the localization of genes on CVS chromosomes, in comparison with known DNA markers.

Binding Sites↗

PubMed2007

Maternal complex chromosome rearrangements involving five chromosomes 1, 4, 10, 12 and 20 ascertained through a del(4)(p14p15) detected in a mother's first affected daughter.

Complex chromosomal rearrangements, defined as exchanges between three or more chromosomes, are very rare aberrations in human chromosomal pathology. We present a case of a complex, apparently balanced maternal chromosome rearrangement involving five different chromosomes (1, 4, 10, 12 and 20) and six breakpoints ascertained through a deletion of the short arm of chromosome 4 [del(4)(p14p15)] detected in a mother's affected 2-year old daughter.

Abnormalities, Multiple↗

PubMed1996

The human CAS (cellular apoptosis susceptibility) gene mapping on chromosome 20q13 is amplified in BT474 breast cancer cells and part of aberrant chromosomes in breast and colon cancer cell lines.

The CAS (cellular apoptosis susceptibility) gene is the human homolog of the yeast chromosome segregation gene CSE1. CAS may have a dual function in mammalian cells, one in apoptosis and another in cell proliferation. We have now mapped the CAS gene to chromosome 20q13. This region is known to harbor amplifications that correlate with aggressive breast cancer. Southern hybridizations with a CAS cDNA fragment and fluorescent in situ hybridization (FISH) with a P1 clone containing the CAS gene show elevated copy numbers in one leukemia, three of four colon, and in three of seven breast cancer cell lines. Elevated CAS copy number in CEM leukemia and COLO201 colon cancer cells was attributable to additional copies of chromosome 20. In SW480 and COLO205 colon cancer cells CAS is part of aberrant chromosomes containing large parts of 20q. In breast cancer cells CAS is also part of aberrant 20q chromosomes (MDA-MB-157 and UACC-812) or of additional 20q isochromosome in MDA-MB-134. In MDA-MB361 and BT-474 breast cancer cells CAS is separated from other markers centromeric and telomeric of CAS on 20q. MDA-MB 361 contains one additional copy of CAS, separated from the centromeric 20q control probe. BT-474 cells have up to 12 additional CAS copies that we separated from nearby telomeric and centromeric probes on 20q and that are translocated to abnormal chromosomes.

Blotting, Southern↗

PubMed2006

Loss of chromosome 1 in myxopapillary ependymoma suggests a region out of chromosome 22 as critical for tumour biology: a FISH analysis of four cases on touch imprint smears.

OBJECTIVE: Ependymomas are glial tumours. They constitute approximately 5-10% of intracranial tumours and are tumours which can recur. Predictive factors of outcome in ependymomas are not well established. Karyotypic studies are relatively scarce and loss of chromosome 22 has been described to correlate with recurrence. We are unaware of any reports involving chromosome 1 aberrations in the malignant progression of ependymomas. METHODS: Cytogenetic analysis of four myxopapillary ependymomas was performed using double target fluorescent in situ hybridization (FISH), focusing on chromosomes 1 and 22. RESULTS: One patient's tumour had recurred. FISH was performed on 500 nuclei/tumours. All four cases showed a loss of chromosome 22q while only one showed an additional loss of chromosome 1p, and this was the one that recurred. CONCLUSIONS: We support the presence of a tumour suppressor gene on 1p associated with relapse in myxopapillary ependymomas and suggest that status of chromosome 1p by FISH may indicate a high-risk group of patients harbouring this tumour. More studies of this type are needed towards this direction as our results refer to a minimal number of individuals analysed.

Adult↗

PubMed2004

A chromosomal analysis of some water beetle species recently transferred from Agabus Leach to Ilybius Erichson, with particular reference to the variation in chromosome number shown by I. montanus Stephens (Coleoptera: Dytiscidae).

The karyotypes of seven Ilybius species are described and illustrated. All except I. wasastjernae have a basic karyotype of 34 autosomes plus sex chromosomes which are X0 ( male symbol ), XX ( female symbol ), with the X chromosome among the largest in the nucleus. This karyotype appears to be the norm for Ilybius and supports the transfer of the species concerned from Agabus to Ilybius. I. wasastjernae has 36 autosomes and the X chromosome is the smallest in the nucleus and its karyotype is unlike any other known karyotype in either Ilybius or Agabus. In most of the species studied no intraspecific variation has been detected. Exceptions are I. chalconatus, where there is one inversion polymorphism in one of the autosomes, and I. montanus whose autosome number has been found to vary from 29 to 34. Such variation is highly unusual among Coleoptera. The variation results from fusion-fission polymorphisms involving three different pairs of autosomes. In each case the fusions may be homozygous, heterozygous or absent. All populations investigated were polymorphic for some of the fusions, but only one (La Salceda, Spain) included individuals lacking all fusions. The frequencies of fused and unfused chromosomes were analysed in three English populations. In only one case was there a departure from the values expected from the Hardy-Weinberg equilibrium, and this population also showed a significant difference from the other two. Meiosis in males heterozygous for fusions involves the production of trivalents in first division, but results in the production of abundant sperm, with no evidence of chromosomal abnormalities in second metaphase, or of degenerating cells as a result of failed meiosis. The three fusions sites are consistent in all the populations studied, and it is concluded that these fusions represent unique historical events rather than current chromosomal instability.

Animals↗

PubMed1991

Localization of the human gene allowing infection by gibbon ape leukemia virus to human chromosome region 2q11-q14 and to the homologous region on mouse chromosome 2.

Retrovirus receptors remain a largely unexplored group of proteins. Of the receptors which allow infection of human and murine cells by various retroviruses, only three have been identified at the molecular level. These receptors include CD4 for human immunodeficiency virus, Rec-1 for murine ecotropic virus, and GLVR1 for gibbon ape leukemia virus. These three proteins show no homology to one another at the DNA or protein level. Therefore, work to date has not shown any general relationship or structural theme shared by retroviral receptors. Genes for two of these receptors (CD4 and Rec-1) and several others which have not yet been cloned have been localized to specific chromosomes. In order to assess the relationship between GLVR1 and other retroviral receptors, we mapped the chromosome location of GLVR1 in human and mouse. GLVR1 was found to map to human chromosome 2q11-q14 by in situ hybridization and somatic-cell hybrid analysis. This location is distinct from those known for receptors for retroviruses infecting human cells. Glvr-1 was then mapped in the mouse by interspecies backcrosses and found to map to chromosome 2 in a region of linkage conservation with human chromosome 2. This mouse chromosome carries Rec-2, the likely receptor for M813, a retrovirus derived from a feral Asian mouse. These data raise the interesting possibility that Rec-2 and Glvr-1 are structurally related.

Animals↗

PubMed1980

Female phenotype and multiple abnormalities in sibs with a Y chromosome and partial X chromosome duplication: H--Y antigen and Xg blood group findings.

A mentally retarded female child with multiple congenital abnormalities had an abnormal X chromosome and a Y chromosome; the karyotype was interpreted as 46,dup(X)(p21 leads to pter)Y. Prenatal chromosome studies in a later pregnancy indicated the same chromosomal abnormality in the fetus. The fetus and proband had normal female genitalia and ovarian tissue. H--Y antigen was virtually absent in both sibs, a finding consistent with the view that testis-determining genes of the Y chromosome may be suppressed by regulatory elements of the X. The abnormal X chromosome was present in the mother, the maternal grandmother, and a female sib: all were phenotypically normal and showed the karyotype 46,Xdup(X)(p21 leads to pter) with non-random inactivation of the abnormal X. Anomalous segregation of the Xga allele suggests that the Xg locus was involved in the inactivation process or that crossing-over at meiosis occurred.

Abnormalities, Multiple↗

PubMed1992

Reverse chromosome painting: a method for the rapid analysis of aberrant chromosomes in clinical cytogenetics.

We describe a method, termed reverse chromosome painting, which allows the rapid analysis of the content and breakpoints of aberrant chromosomes. The method involves the sorting of small numbers of the aberrant chromosome from short term blood culture preparations or cell lines by using bivariate flow karyotype analysis. The sorted chromosomes are amplified and biotin labelled enzymatically using a degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR), the product annealed to metaphase spreads from normal subjects, and hybridisation detected using fluorescence in situ hybridisation (FISH). We show the usefulness of this method for routine clinical cytogenetics by the analysis of cases involving an insertion, a deletion, a translocation, and two cases of a chromosome with additional material of unknown origin. The method has particular application for the rapid resolution of the origin of de novo unbalanced chromosome duplications.

Adult↗