Regional mapping on human genes for phosphoglucomutase-1 on chromosome 1 and beta-glucuronidase on chromosome 7 using mouse x human hybrids.

Two independent mouse-human somatic cell hybrid clones contained different, de novo chromosome rearrangements involving the short arm of human chromosome 1. One hybrid clone contained a translocation between human chromosomes 1 and 7; the other clone contained a rearrangement product between human chromosomes 1 and 14. Analysis of these clones for expression of genes previously assigned to chromosome 7 and to the short arm of chromosome 1 provided evidence for localization of PGM--1 in segment 1p22.1 leads to 1p31.1, AK--2, ENO--1 and UMPK in region 1pter leads to 1p31.1, and GUS in region 7 pter leads to 7q22. The results have been used to examine the relationship between cytologic and genetic map distances on the short arm of chromosome 1.     

Cytogenetic,oncogenetic, and histopathologic characteristics of colorectal carcinomas with 17p abnormalities

Summary From a total of 65 colorectal adenocarcinomas studied by cytogenetic methods, 33 were selected for the present study; in addition to other karyotypic anomalies, these 33 showed a loss of the short arm of chromosome 17. This loss was either the result of a deletion or rearrangement, or caused by the loss of a whole chromosome 17. The 17p-tumors were characterized by a high grade of karyotypic abnormality including a high incidence of cases with double minutes. A gain of chromosomes 2, 7, 19, and 20, and the loss of chromosome 18 and the Y-chromosome were the most frequent numerical anomalies associated with 17p-, as were structural changes of chromosomes 1 and 5. The most impressive difference in the pattern of proto-oncogene over-expression between the 17p-tumors and those without this anomaly was the significantly increased frequency of cases with c-erbB over-expression. Some significant, but also loose, associations were found between cytogenetic/ oncogenetic and histopathologic or clinical features of these tumors. The patterns of genetic changes in cells of colorectal carcinomas may thus reflect the potential of the future development, rather than the present clinical features, of the respective tumor. Therefore, the character of the change seems to be more prognostic than diagnostic.     

Karyotype pecularities of human colorectal adenocarcinomas

Summary The data of the chromosome abnormalities in 15 colorectal tumors are presented. Rearrangements of the short arm of chromosome 17, leading to deletions of this arm or its part were noted in 12 tumors; in 2 other cases, one of the homologs of pair 17 was lost. The losses of at least one homolog of other chromosomal pairs were also found: chromosome 18, in 12 out of 13 cases with fully identified numerical abnormalities; chromosome 5, in 6 tumors; chromosome 21, in 5 cases; chromosomes 4, 15, and 22, in 4 cases each. Additional homologs of pair 20 were observed in 6 tumors, extra 8q was found in 5 tumors, and extra 13q in 6 cases. Rearrangements of the short arm of chromosome 1 and the long arm of chromosome 11 characterized 6 tumors each. The data recorded in our series differ from the data of other authors in two respects: the high incidence of the loss of sex chromosomes and the rearrangements of the long arm of chromosome 9. X chromosomes were missing in 4 out of 7 tumors in females, and Y chromosomes were absent in 5 out of 8 tumors in males. The long arm of chromosome 9 was rearranged in 8 cases, in 5 of them the breakpoint being at 9q22. Cytological manifestations of gene amplification (double minutes or multiple microchromosomes) were noted in 6 tumors.     

Abnormalities of chromosome No. 1: significance in malignant transformation.

Studies of human hematologic malignancies have provided sufficient data not only for the identification of nonrandom abnormalities of whole chromosomes, but also for determination of the specific chromosome regions involved. In clonal aberrations leading to an excess of chromosome No. 1, or a partial excess of No. 1, trisomy for bands 1q25 to 1q32 was noted in the myeloid cells obtained from every one of 35 patients who had various disorders, such as acute leukemia, polycythemia vera, or myelofibrosis. Similar chromosome changes were a consistent finding in various solid tumors as well. This rearrangement was not the result of a particularly fragile site in that region of the chromosome, since the break points in reciprocal translocations that involve No. 1 occurred almost exclusively in the short arm. The nonrandom chromosome changes found in neoplastic cells can now be correlated with the gene loci on these chromosomes or chromosome segments as an attempt is made to identify specific genes that might be related to malignancy.     

Regulation of rRNA gene expression in a human familial 14p+ marker chromosome

Summary Chromosome studies were carried out on normal individuals from three generations of one family with a 14p+ chromosome. The short arm of the 14p+ chromosome stained well using Giemsa but poorly using quinacrine or trypsin-Giemsa methods; in each case there was an unstained secondary constriction near the distal end of the short arm. Two Ag bands of average size were present on the 14p+ short arm, indicating that there were two active nucleolus organizer regions; the Ag band near the distal end of the short arm was slightly larger than that near the centromere. Each of the two Ag bands was seen associated with the short arm of one or more of the other acrocentric chromosomes, with a combined frequency of association no greater than that of other chromosomes with an Ag band of the same size. In one individual, hybridization in situ with radioactive 18S and 28S ribosomal RNA showed six times as many autoradiographic silver grains over the short arm of the 14p+ chromosome as over that of any other acrocentric chromosome. The results obtained using in situ labeling indicated that the 14p+ chromosome had a large number of rRNA genes compared with the other acrocentric chromosomes, whereas the results obtained using Ag-staining and association frequency indicated that the 14p+ chromosome had no greater nucleolus organizer activity than did the other acrocentrics. The difference in these findings suggests that not all the rRNA genes on the 14p+ chromosome were active.     

Rearrangement of the chromosome 17 in colonic adenocarcinoma

Chromosome studies on five cases of large bowel adenocarcinoma show a systematic rearrangement of chromosome No. 17 after breakage in its juxtacentromeric region (band 17 q 11). A frequent involvement of chromosome No. 8 (juxtacentromeric break) and the loss of chromosome No. 18 are also noticed. A review of the literature strengthens the hypothesis of a preferential involvement of these chromosomes in large bowel cancer.     

Frequent occurrence of translocations of the short arm of chromosome 15 to other D-group chromosomes

Summary The presence of DA/DAPI (distamycin A/ 4,6-diamino-2-phenyl-indole) heteromorphism on the short arm of human acrocentric chromosomes was investigated in 127 individuals. In 7 cases, a DA/DAPI signal was observed on an acrocentric chromosome other than 15. Subsequently, in situ hybridization (ISH) with a pericentromeric probe specific for chromosome 15 was carried out. In all 7 cases, three ISH signals were present in every metaphase, i.e., on both chromosomes 15 and on the third DA/DAPI-fluorescence-positive acrocentric chromosome (a chromosome 13 or 14), indicating that a chromosome 15 short arm was also present on these chromosomes. Therefore, we conclude that translocations of short arm sequences from chromosome 15 onto other D-group chromosomes occur frequently. Moreover, it appears that DA/DAPI staining remains specific for the short arm of chromosome 15, despite a number of recent papers suggesting otherwise.     

Rye chromosome translocations in hexaploid wheat: a re-evaluation of the loss of heterochromatin from rye chromosomes

Summary Using in situ hybridization techniques, we have been able to identify the translocated chromosomes resulting from whole arm interchanges between homoeologous chromosomes of wheat and rye. This was possible because radioactive probes are available which recognize specific sites of highly repeated sequence DNA in either rye or wheat chromosomes. The translocated chromosomes analysed in detail were found in plants from a breeding programme designed to substitute chromosome 2R of rye into commercial wheat cultivars. The distribution of rye highly repeated DNA sequences showed modified chromosomes in which (a) most of the telomeric heterochromatin of the short arm and (b) all of the telomeric heterochromatin of the long arm, had disappeared. Subsequent analyses of these chromosomes assaying for wheat highly repeated DNA sequences showed that in type (a), the entire short arm of 2R had been replaced by the short arm of wheat chromosome 2B and in (b), the long arm of 2R had been replaced by the long arm of 2B. The use of these probes has also allowed us to show that rye heterochromatin has little effect on the pairing of the translocated wheat arm to its wheat homologue during meiosis. We have also characterized the chromosomes resulting from a 1B-1R translocation event.From these results, we suggest that the observed loss of telomeric heterochromatin from rye chromosomes in wheat is commonly due to wheat-rye chromosome translocations.     

Preferential derivation of abnormal human G-group-like chromosomes from chromosome 15

Summary The marked binding of antibodies specific for 5-methylcytidine to the short arm of chromosome 15 distinguishes this chromosome from the other human acrocentrics. This method has been used to study over 60 individuals including 12 who did not have Down's syndrome, but who did have an extra G-group sized acrocentric chromosome. In six cases the extra chromosome did not show intensive binding of anti-5-methylcytidine. In the other six cases, the extra chromosome contained a 5-methylcytidine rich band at each end indicating that both ends were derived from chromosome 15 and contained centromeric heterochromatin normally present on the short arm of chromosome 15. The duplication of short arm material in the abnormal chromosomes was confirmed in all cases by quinacrine staining, nucleolar organizer (Ag-AS) staining or C-banding. In three cases, the abnormal chromosome appeared to arise from two different chromosomes 15. Several possible mechanisms for the production of the abnormal chromosome are discussed. The individuals with this abnormal chromosome all showed some degree of mental retardation, but few common physical findings.     

Unique genomic sequences in human chromosome 16p are conserved in the great apes

In humans, acute myelomonocytic leukemia (AMML) with abnormal bone marrow eosinophilia is diagnosed by the presence of a pericentric inversion in chromosome 16, involving breakpoints p13;q23 [i.e., inv(16)(p13;q23)]. A pericentric inversion involves breaks that have occurred on the p and q arms and the segment in between is rotated 180° and reattaches. The recent development of a “human micro-coatasome” painting probe for 16p contains unique DNA sequences that fluorescently label only the short arm of chromosome 16, which facilitates the identification of such inversions and represents an ideal tool for analyzing the “divergence/convergence” of the equivalent human chromosome 16 (PTR 18, GGO 17 and PPY 19) in the great apes, chimpanzee, gorilla and orangutan. When the probe is used on the type of pericentric inversion characteristic of AMML, signals are observed on the proximal portions (the regions closest to the centromere) of the long and short arms of chromosome 16. The probe hybridized to only the short arm of all three ape chromosomes and signals were not observed on the long arms, suggesting that a pericentric inversion similar to that seen in AMML has not occurred in any of these great apes. Received: 4 July 1996 / Accepted: 18 September 1996     

Identification of a homeologous chromosome pair by in situ DNA hybridization to ribosomal RNA loci in meiotic chromosomes of cotton (Gossypium hirsutum).

In situ DNA hybridization with 18S-28S and 5S ribosomal DNA probes was used to map 18S-28S nucleolar organizers and tandem 5S repeats to meiotic chromosomes of cotton (Gossypium hirsutum L.). Mapping was performed by correlating hybridization sites to particular positions in translocation quadrivalents. Arm assignment required translocation quadrivalents with at least one interstitial chiasma and sufficient distance between the hybridization site and the centromere. We had previously localized a major 18S-28S site to the short arm of chromosome 9; here we mapped two additional major 18S-28S sites to the short arm of chromosome 16 and the left arm of chromosome 23. We also identified and mapped a minor 18S-28S site to the short arm of chromosome 7. Two 5S sites of unequal size were identified, the larger one near the centromere of chromosome 9 and the smaller one near the centromere of chromosome 23. Synteny of 5S and 18S-28S sites indicated homeology of chromosomes 9 and 23, while positions of the other two 18S-28S sites supplement genetic evidence that chromosomes 7 and 16 are homeologous.     

Significance of chromosome 5 and 17 changes in the development of carcinoma of the cervix uteri

Two chromosomes that undergo nonrandom changes in carcinoma of the cervix and have been studied for several decades in this laboratory are discussed. The first, chromosome 5, is discussed in view of the frequent appearance of an isochromosome for 5p, often in two or more copies and commonly associated with fewer that the expected number of normal copies of this chromosome. The second is chromosome 17, where a translocation involving another chromosome may result in a 17p+, and the significant change appears to be a loss from 17p that may include the p53 gene (TP53) and/or other tumor-suppressor genes located on this chromosome arm.     

Detection of single-copy genes and chromosome rearrangements in Petunia hybrida by fluorescence in situ hybridization

DNA sequences homologous to single-copy genes were labelled with biotinylated dUTP or digoxygenin-labelled dUTP and hybridized to chromosome spreads. The hybridization signals were visualized with fluorescent avidin- or antibody-conjugates. This method allowed the detection of DNA targets on metaphase chromosomes as small as 1.4 kb. The hybridization signals were identified as fluorescent spots on both sister chromatids. Using an 18S rDNA probe as marker to identify chromosomes II and III it was possible to assign single-copy genes to these chromosomes. In the line V30 the endogenous chalcone synthase gene (chsA) was mapped at the distal end of the short arm of chromosome 5. The cDNA probe for this single-copy gene was 1.4 kb. In contrast, in the lines Mitchell and V26 chsA was localized at the distal end of the long arm of chromosome 3, suggesting that a chromosomal rearrangement had taken place. In a transformed Petunia uidA, transgenes were detected using a 2.7 kb probe. One transgene was mapped on one of the homologues of chromosome II proximal to the ribosomal genes. This homologue could be distinguished from the other by having the ribosomal genes at the distal end of the long arm. Using multicolour fluorescence in situ hybridization it was shown that it is possible to detect the endogenous chsA genes and both transgenes simultaneously.     

Karyotypes of three somaclonal variants and wild plants ofAllium tuberosum by bicolor FISH

Using the fluorescence in situ hybridization (FISH) technique, we conducted karyotype analyses to identify the lost chromosomes in three somaclonal variants obtained from tissue culture of wildAllium tuberosum (2n = 4X = 32). The three lost chromosomes of the At29 variant (2n = 29) were all chromosome 2, the two for At30 (2n = 30) were chromosomes 7 and 8, and At31 was missing chromosome 2. Chromosome compositions of these variants were confirmed as being fixed lines during two years of greenhouse cultivation. The bicolor FISH technique, involving both 5S and 18S–5.8S–26S ribosomal RNA genes as probes, was used to assign chromosomal locations and to confirm whether the lost chromosomes contained any rRNA markers. The 5S rRNA gene signals in all variants as well as the wild type were detected as two sets, one on the intercalary region of the short arm of chromosome 3, the other on the intercalary region of the long arm of chromosome 6. One 18S–5.8S–26S rRNA gene site on the secondary constriction included a flanking satellite and terminal region on the short arm of chromosome 8. Signals of the 18S–5.8S–26S rRNA gene in At30 showpd in only three chromosomes, indicating that one of the lost chromosomes was chromosome 8. Overall, three marker chromosomes were established by FISH, using rRNA multigene families.     

Frequency of chromosome variants in human populations]

Chromosome variants were analyzed in the course of the population chromosome investigation of 6000 newborns and clinical cytogenetic studies of 403 married couples with recurrent spontaneous abortions, stillbirths or offsprings having congenital malformations or Down's syndrome. The following variants were determined: 1) Igh+, 9gh+, 16gh+ - the enlargement of the secondary constrictions of the size, more than 1/4 of the long arm of the chromosome; 2) Dp+ or Gp+ - the enlargement of the short arms of acrocentrics, their size being more than the short arm of the chromosome 18; 3) Ds+ or Gs - large satellites of the acrocentrics which are equal or more than the thickness of the chromatids of the long arms; 4) Es+ - satellites on the short arms of the chromosomes 17 or 18; 5) Dss of Gss - double satellites; 6) Yq+ - the enlargement of the long arm of Y chromosome, the size of which being more than G chromosome; 7) Yq- - deletion of the long arm of Y chromosome, the size of the long arm being less than chromosomes 21--22. The total frequency of variants in newborns was 12.8/1000 births. The incidence of different types of variants per 1000 births was as follows: Igh+ - 0.33; 9gh+ - 0.17; 16gh+ - 0.50; Ds+ - 2.33; Dp+ - 1.50; Dp- - 0.17; Gs+ - 0.83; Gp+ - 2.17; Yq+ - 6.91/1000 males; Yg- - 0.99/1000 males; double variants - 0.33; other variants - 0.33. 4.0% of married couples with recurrent spontaneous abortions had major chromosome aberrations, 14.6% - extreme variants of chromosomes. Among 113 couples with the history of congenital malformations in their offsprings major chromosome abnormalities were found in 4.4%, chromosome variants - 13.3%. The frequency of chromosome variants among 139 patients with Down's syndrome was 7.2%. In one case Robertsonian translocation t(DqGa) was determined. The most frequent types of variant chromosomes were Ds+, Dp+, Es+, Yq+.     

Physical mapping of the 5S ribosomal RNA genes in Arabidopsis thaliana by multi-color fluorescence in situ hybridization with cosmid clones

The 5S ribosomal RNA genes were mapped to mitotic chromosomes of Arabidopsis thaliana by fluorescence in situ hybridization (FISH). In the ecotype Landsberg erecta, hybridization signals appeared on three pairs of chromosomes, two of which were metacentric and the other acrocentric. Hybridization signals on one pair of metacentric chromosomes were much stronger than those on the acrocentric and the other pair of metacentric chromosomes, probably reflecting the number of copies of the genes on the chromosomes. Other ecotypes, Columbia and Wassilewskija, had similar chromosomal distribution of the genes, but the hybridization signals on one pair of metacentric chromosomes were very weak, and detectable only in chromosomes prepared from young flower buds. The chromosomes and arms carrying the 5S rDNA were identified by multi-color FISH with cosmid clones and a centromeric 180 bp repeat as co-probes. The metacentric chromosome 5 and its L arm carries the largest cluster of the genes, and the short arm of acrocentric chromosome 4 carries a small cluster in all three ecotypes. Chromosome 3 had another small cluster of 5S rRNA genes on its L arm. Chromosomes 1 and 2 had no 5S rDNA cluster, but they are morphologically distinguishable; chromosome 1 is metacentric and 2 acrocentric. Using the 5S rDNA as a probe, therefore, all chromosomes of A. thaliana could be identified by FISH. Chromosome 1 is large and metacentric; chromosome 2 is acrocentric carrying 18S-5.8S-25S rDNA clusters on its short arm; chromosome 3 is metacentric carrying a small cluster of 5S rDNA genes on its L arm; chromosome 4 is acrocentric carrying both 18S-5.8S-25S and 5S rDNAs on its short (L) arm; and chromosome 5 is metacentric carrying a large cluster of 5S rDNA on its L arm.     

The mobile nature of acrocentric elements illustrated by three unusual chromosome variants

Variant chromosomes are polymorphic in areas that are rich in repeat sequences such as the pericentromeric regions or in the acrocentric short arm regions. The dynamic nature of these regions is evident in the polymorphisms they exhibit. In this paper three unusual variants are described: a chromosome 21 with additional material on its short arm, a chromosome 7 with an insertion in the short arm and a chromosome 2 with satellites at the end of the long arm. All three variants were shown to involve acrocentric elements using special banding techniques and fluorescence in situ hybridization. The 21 variant was found to be a tricentric with a 21 and two 15 alpha-, two classical and three acrocentric beta-satellite signals interspersed by AgNOR-positive regions. The telomeres were present at the two terminal ends. The insertion on chromosome 7 was found to be C-band positive and to contain acrocentric beta-satellite DNA. However, acrocentric alpha-satellite, classical satellite, whole-chromosome-painting or all-telomeres sequence probes did not hybridize to the insertion. The satellited region of chromosome 2 had two C-bands, a small positive all-centromeres probe signal, and two signals for the beta-satellite probe. Sandwiched between the beta-satellite sequences was an AgNOR-positive region. The telomeres were present at the two ends of the satellited chromosome 2. Chromosome 2 subtelomeric probes hybridized to the terminal ends of the short and long arm of chromosome 2. The common thread in these three variants is the involvement of acrocentric short arm elements. The acrocentric short arm elements are shown to move to other acrocentric or nonacrocentric chromosomes and relocate to both terminal and interstitial positions. The integrations are stable and heritable. Received: 23 September 1997 / Accepted: 23 February 1998     

A molecular deletion of distal chromosome 4p in two families with a satellited chromosome 4 lacking the Wolf-Hirschhorn syndrome phenotype.

We report two families with a satellited chromosome 4 short arm (4ps). Satellites and stalks normally occur on the short arms of acrocentric chromosomes; however, the literature cites several reports of satellited nonacrocentric chromosomes, which presumably result from a translocation with an acrocentric chromosome. This is the first report of 4ps chromosomes. Our families are remarkable in that both unaffected and affected individuals carry the 4ps chromosome. The phenotypes observed in affected individuals, although dissimilar, were sufficient to encourage a search for a deletion of chromosome 4p. By Southern blot analysis and fluorescence in situ hybridization, a deletion of material mapping approximately 150 kb from chromosome 4pter was discovered. This deletion is notable because it does not result in the Wolf-Hirschhorn syndrome and can result in an apparently normal phenotype. We speculate that homology between subterminal repeat sequences on 4p and sequences on the acrocentric short arms may explain the origin of the rearrangement and that position effect may play a role in the expression of the abnormal phenotype.     

Characterization of a rare short arm heteromorphism of chromosome 22 in a girl with down-syndrome like facies

Chromosomal heteromorphisms are described as interindividual variation of chromosomes without phenotypic consequence. Chromosomal polymorphisms detected include most regions of heterochromatin of chromosomes 1, 9, 16 and Y and the short arms of all acrocentric chromosomes. Here, we report a girl with Down-syndrome such as facies and tremendously enlarged short arm of a chromosome 22. Fluorescence in situ hybridization (FISH) with a probe specific for all acrocentric short arms revealed that the enlargement p arms of the chromosome 22 in question contained exclusively heterochromatic material derived from an acrocentric short arm. Parental studies identified a maternal origin of this heteromorphism. Cryptic trisomy 21 of the Down-syndrome critical region was excluded by a corresponding FISH-probe. Here, we report, to the best of our knowledge, largest ever seen chromosome 22 short arm, being ~×1.5 larger than the normal long arm.     

Cerebellar dysgenesis and mental retardation associated with a complex chromosome rearrangement

Cerebellar hypoplasia, mild mental retardation, skeletal abnormalities, and ataxia were present in a 40 years old patient with a complex chromosome rearrangement (CCR). Chromosomes 2, 5, 16, and 17 were involved in the CCR. For the definition of the eight breakpoints leading to the rearrangement FISH with whole chromosomes paintings and specific telomeric probes was employed. Gene disruption, positional effect variegation, and sub-microscopic deletions are all possible causes for the abnormal phenotype observed in the patient.