Showing papers on "Chromosome 22 published in 1998"
TL;DR: The observation of bi-allelic alterations of hSNF5/INI1 in MRTs suggests that loss-of-function mutations of h snf5/inI1 contribute to oncogenesis, and the most frequently deleted part of chromosome 22q11.2 is mapped.
Abstract: Malignant rhabdoid tumours (MRTs) are extremely aggressive cancers of early childhood. They can occur in various locations, mainly the kidney, brain and soft tissues. Cytogenetic and molecular analyses have shown that the deletion of region 11.2 of the long arm of chromosome 22 (22q11.2) is a recurrent genetic characteristic of MRTs, indicating that this locus may encode a tumour suppressor gene. Here we map the most frequently deleted part of chromosome 22q11.2 from a panel of 13 MRT cell lines. We observed six homozygous deletions that delineate the smallest region of overlap between the cell lines. This region is found in the hSNF5/INI1 gene, which encodes a member of the chromatin-remodelling SWI/SNF multiprotein complexes. We analysed the sequence of hSNF5/INI1 and found frameshift or nonsense mutations of this gene in six other cell lines. These truncating mutations of one allele were associated with the loss of the other allele. Identical alterations were observed in corresponding primary tumour DNAs but not in matched constitutional DNAs, indicating that they had been acquired somatically. The observation of bi-allelic alterations of hSNF5/INI1 in MRTs suggests that loss-of-function mutations of hSNF5/INI1 contribute to oncogenesis.
1,402 citations
TL;DR: It is demonstrated by quantitative fluorescence in situ hybridization that the number of T2AG3 repeats on specific chromosome arms is very similar in different tissues from the same donor and varies only to some extent between donors, raising the possibility that the relatively short telomeres on chromosome 17p contribute to the frequent loss of 17p alleles in human cancers.
Abstract: Human chromosomes terminate in a series of T2AG3 repeats, which, together with associated proteins, are essential for chromosome stability. In somatic cells, these sequences are known to be gradually lost through successive cells divisions; however, information about changes on specific chromosomes is not available. Individual telomeres could mediate important biological effects as was shown in yeast, in which loss of a single telomere results in cell-cycle arrest and chromosome loss. We now demonstrate by quantitative fluorescence in situ hybridization (Q-FISH; ref. 7) that the number of T2AG3 repeats on specific chromosome arms is very similar in different tissues from the same donor and varies only to some extent between donors. In all sixteen individuals studied, telomeres on chromosome 17p were shorter than the median telomere length--a finding confirmed by analysis of terminal restriction fragments from sorted chromosomes. These observations provide evidence of chromosome-specific factors regulating the number of T2AG3 repeats in individual telomeres and raise the possibility that the relatively short telomeres on chromosome 17p contribute to the frequent loss of 17p alleles in human cancers.
345 citations
TL;DR: Pedigree analysis established that DSBs occurring in G1 were repaired by a replicative mechanism, producing two identical daughter cells, and discusses the implications of these data in understanding telomerase-independent replication of telomeres, gene amplification, and the evolution of chromosomal ends.
Abstract: In yeast, broken chromosomes can be repaired by recombination, resulting in nonreciprocal translocations. In haploid cells suffering an HO endonuclease-induced, double-strand break (DSB), nearly 2% of the broken chromosome ends recombined with a sequence near the opposite chromosome end, which shares only 72 bp of homology with the cut sequence. This produced a repaired chromosome with the same 20-kb sequence at each end. Diploid strains were constructed in which the broken chromosome shared homology with the unbroken chromosome only on the centromere-proximal side of the DSB. More than half of these cells repaired the DSB by copying sequences distal to the break from the unbroken template chromosome. All these events were RAD52 dependent. Pedigree analysis established that DSBs occurring in G1 were repaired by a replicative mechanism, producing two identical daughter cells. We discuss the implications of these data in understanding telomerase-independent replication of telomeres, gene amplification, and the evolution of chromosomal ends.
222 citations
TL;DR: These unusual DNA characteristics are possibly intrinsic properties of common fragile sites that may affect their replication and condensation as well as organization, and may lead to fragility.
Abstract: Common fragile sites are chromosomal loci prone to breakage and rearrangement, hypothesized to provide targets for foreign DNA integration. We cloned a simian virus 40 integration site and showed by fluorescent in situ hybridization analysis that the integration event had occurred within a common aphidicolin-induced fragile site on human chromosome 7, FRA7H. A region of 161 kb spanning FRA7H was defined and sequenced. Several regions with a potential unusual DNA structure, including high-flexibility, low-stability, and non-B-DNA-forming sequences were identified in this region. We performed a similar analysis on the published FRA3B sequence and the putative partial FRA7G, which also revealed an impressive cluster of regions with high flexibility and low stability. Thus, these unusual DNA characteristics are possibly intrinsic properties of common fragile sites that may affect their replication and condensation as well as organization, and may lead to fragility.
216 citations
01 Sep 1998
TL;DR: In this article, the arrangement of chromosome DNA within the bacterium Bacillus subtilis was investigated by using fluorescence microscopy to visualize two sites on the chromosome simultaneously in the same cell.
Abstract: Background: The contour length of the circular chromosome of bacteria is greater than a millimeter but must be accommodated within a cell that is only a few micrometers in length. Bacteria do not have nucleosomes and little is known about the arrangement of the chromosome inside a prokaryotic cell. Results: We have investigated the arrangement of chromosomal DNA within the bacterium Bacillus subtilis by using fluorescence microscopy to visualize two sites on the chromosome simultaneously in the same cell. Indirect immunofluorescence with antibodies against the chromosome partition protein Spo0J were used to visualize the replication origin region of the chromosome. Green fluorescent protein fused to the lactose operon repressor Lacl was used to decorate tandem copies of the lactose operon operator lacO . A cassette of tandem operators was separately inserted into the chromosome near the origin (359°), near the replication terminus (181°), or at two points in between (90° and 270°). The results show that the layout of the chromosome is dynamic but is principally arranged with the origin and terminus maximally apart and the quarter points of the chromosome in between. Conclusions: The use of cytological methods to visualize two chromosomal sites in the same cell has provided a glimpse of the arrangement of a bacterial chromosome. We conclude that, to a first approximation, the folding of the bacterial chromosome is consistent with, and may preserve, the linear order of genes on the DNA.
194 citations
TL;DR: The use of cytological methods to visualize two chromosomal sites in the same cell has provided a glimpse of the arrangement of a bacterial chromosome and it is concluded that the folding of the bacterial chromosome is consistent with, and may preserve, the linear order of genes on the DNA.
191 citations
TL;DR: It is shown that major chromosomal rearrangements can occur upon T-DNA transformation of Arabidopsis thaliana, and a large inversion occurs on the bottom arm of chromosome 2, which strongly suggest a reciprocal translocation between chromosomes 2 and 3.
Abstract: We show that major chromosomal rearrangements can occur upon T-DNA transformation of Arabidopsis thaliana. In the ACL4 line, two T-DNA insertion loci were found; one is a tandem T-DNA insert in a head-to-head orientation, and the other is a truncated insert with only the left part of the T-region. The four flanking DNA regions were isolated and located on the Arabidopsis chromosomes; for both inserts, one side of the T-DNA maps to chromosome 2, whereas the other side maps to chromosome 3. Both chromosome 3 flanking regions map to the same location, despite a 1.4-kb deletion at this point, whereas chromosome 2 flanking regions are located 40 cM apart on the bottom arm of chromosome 2. These results strongly suggest a reciprocal translocation between chromosomes 2 and 3, with the breakpoints located at the T-DNA insertion sites. The interchanged fragments roughly correspond to the 20-cM distal ends of both chromosomes. Moreover, a large inversion, spanning 40 cM on the genetic map, occurs on the bottom arm of chromosome 2. This was confirmed by genetic analyses that demonstrated a strong reduction of recombination in the inverted region. Models for T-DNA integration and the consequences for T-DNA tagging are discussed in light of these results.
181 citations
TL;DR: The poor correlation of physical to genetic distance previously observed in M. grisea appears to be manifested over relatively short distances, and the cloning of avrCO39 is confirmed by directly subcloning the target region after release by Achilles' cleavage.
Abstract: The avrCO39 gene conferring avirulence toward rice cultivar CO39 was previously mapped to chromosome 1 of Magnaporthe grisea between cosegregating markers CH5-120H and 1.2H and marker 5-10-F. In the present study, this region of the chromosome was physically mapped using RecA-mediated Achilles' cleavage. Cleavage of genomic DNA sequences within CH5-120H and 5-10-F liberated a 610-kb restriction fragment, representing the physical distance between these markers. Chromosome walking was initiated from both markers but was curtailed due to the presence of repetitive DNA sequences and the absence of overlapping clones in cosmid libraries representing several genome equivalents. These obstacles were overcome by directly subcloning the target region after release by Achilles' cleavage and a contig spanning avrCO39 was thus assembled. Transformation of two cosmids into a virulent recipient strain conferred a cultivar-specific avirulence phenotype thus confirming the cloning of avrCO39. Meiotic crossover points were unevenly distributed across this chromosomal region and were clustered around the avrCO39 locus. A 14-fold variation in the relationship between genetic and physical distance was measured over the avrCO39 chromosomal region. Thus the poor correlation of physical to genetic distance previously observed in M. grisea appears to be manifested over relatively short distances.
155 citations
TL;DR: From the analysis of several insertion elements, it is presented compelling evidence that the first step in Y chromosome degeneration is driven by the accumulation of transposable elements, especially retrotransposons.
Abstract: Y chromosome degeneration is characterized by structural changes in the chromosome architecture and expansion of genetic inertness along the Y chromosome. It is generally assumed that the heteromorphic sex chromosome pair has developed from a pair of homologues. Several models have been suggested. We use the unique situation of the secondary sex chromosome pair, neo-Y and neo-X (X2), in Drosophila miranda to analyze molecular mechanisms involved in the evolutionary processes of Y chromosome degeneration. Due to the fusion of one of the autosomes to the Y chromosome (about 2 Mya), a neo-Y chromosome and a neo-X chromosome, designated X2, were formed. Thus, formerly autosomal genes are inherited now on a pair of sex chromosomes in D. miranda. Analyzing DNA sequences from the X2 and neo-Y region, we observed a massive accumulation of DNA insertions on the neo-Y chromosome. From the analysis of several insertion elements, we present compelling evidence that the first step in Y chromosome degeneration is driven by the accumulation of transposable elements, especially retrotransposons. An enrichment of these elements along an evolving Y chromosome could account for the switch from a euchromatic into a heterochromatic chromatin structure.
146 citations
TL;DR: Two types of chromosome co‐exist independently in bottom fermenting yeast: one set which originated from S. bayanus and another set from S.
Abstract: The bottom fermenting yeasts in our collection were classified as Saccharomyces pastorianus on the basis of their DNA relatedness. The genomic organization of bottom fermenting yeast was analysed by Southern hybridization using eleven genes on chromosome IV, six genes on chromosome II and five genes on chromosome XV of S. cerevisiae as probes. Gene probes constructed from S. cerevisiae chromosomes II and IV hybridized strongly to the 820-kb chromosome and the 1500-kb chromosome of the bottom fermenting yeast, respectively. Five gene probes constructed from segments of chromosome XV hybridized strongly to the 1050-kb and the 1000-kb chromosomes. These chromosomes are thought to be S. cerevisiae-type chromosomes. In addition, these probes also hybridized weakly to the 1100-kb, 1350-kb, 850-kb and 700-kb chromosome. Gene probes constructed from segments including the left arm to TRP1 of chromosome IV and the right arm of chromosome II hybridized to the 1100-kb chromosomes of S. pastorianus. Gene probes constructed using the right arm of chromosome IV and the left arm of chromosome II hybridized to the 1350-kb chromosome of S. pastorianus. These results suggested that the 1100-kb and 1350-kb chromosomes were generated by reciprocal translocation between chromosome II and IV in S. pastorianus. Three gene probes constructed using the right arm of chromosome XV hybridized weakly to the 850-kb chromosome, and two gene probes from the left arm hybridized weakly to the 700-kb chromosome. These results suggested that chromosome XV of S. cerevisiae was rearranged into the 850-kb and 700-kb chromosomes in S. pastorianus. These weak hybridization patterns were identical to those obtained with S. bayanus. Therefore, two types of chromosome co-exist independently in bottom fermenting yeast: one set which originated from S. bayanus and another set from S. cerevisiae. This result supports the hypothesis that S. pastorianus is a hybrid of S. cerevisiae and S. bayanus.
139 citations
TL;DR: The Streptomyces wild‐type chromosome is linear in all examples studied, but undergoes very large deletions spontaneously at rates higher than 0.1% of spores and RecA seems to be involved in the amplification mechanism and control of genetic instability.
Abstract: The Streptomyces wild-type chromosome is linear in all examples studied. The ends of the chromosome or telomeres consist of terminal inverted repeats of various sizes with proteins covalently bound to their 5' ends. The chromosome is very unstable and undergoes very large deletions spontaneously at rates higher than 0.1% of spores. Frequently, the telomeres are included in the deletions. Loss of both telomeres leads to circularization of the chromosome. The wild-type chromosome can also be circularized artificially by targeted recombination. Spontaneously or artificially circularized chromosomes are even more unstable than the linear ones. High-copy-number tandem amplifications of specific chromosomal regions are frequently associated with the deletions. RecA seems to be involved in the amplification mechanism and control of genetic instability.
TL;DR: The rate of meiotic exchange across the X chromosomes centromere is at least eightfold lower than the average rate of female recombination on the X chromosome and one of the lowest rates of exchange yet observed in the human genome.
Abstract: Classical genetic studies in Drosophila and yeast have shown that chromosome centromeres have a cis-acting ability to repress meiotic exchange in adjacent DNA. To determine whether a similar phenomenon exists at human centromeres, we measured the rate of meiotic recombination across the centromere of the human X chromosome. We have constructed a long-range physical map of centromeric alpha-satellite DNA (DXZ1) by pulsed-field gel analysis, as well as detailed meiotic maps of the pericentromeric region of the X chromosome in the CEPH family panel. By comparing these two maps, we determined that, in the proximal region of the X chromosome, a genetic distance of 0.57 cM exists between markers that span the centromere and are separated by at least the average 3600 kb physical distance mapped across the DXZ1 array. Therefore, the rate of meiotic exchange across the X chromosome centromere is <1 cM/6300 kb (and perhaps as low as 1 cM/17,000 kb on the basis of other physical mapping data), at least eightfold lower than the average rate of female recombination on the X chromosome and one of the lowest rates of exchange yet observed in the human genome.
TL;DR: Ark blot analysis of eutherian and metatherian genomic DNA indicates that X-Y homologues are present in all species tested except simian primates and kangaroo and that retroposons are common to a wide range of mammals.
Abstract: interval of the mouse Y chromosome is criti-cal for spermatogenesis and expression of the male-specific minor transplantation antigen H-Y. Severalgenes have been mapped to this interval and each hasa homologue on the X chromosome. Four, Zfy1, Zfy2,Ube1y and Dffry , are expressed specifically in the testisand their X homologues are not transcribed from theinactive X chromosome. A further two, Smcy and Uty,are ubiquitously expressed and their X homologuesescape X-inactivation. Here we report the identificationof another gene from this region of the mouse Ychromosome. It encodes the highly conserved euka-ryotic translation initiation factor eIF-2γ. In the mousethis gene is ubiquitously expressed, has an X chromo-some homologue which maps close to Dmd and es-capes X-inactivation. The coding regions of the X andY genes show 86% nucleotide identity and encode pu-tative products with 98% amino acid identity. In hu-mans, the eIF-2γ structural gene is located on the Xchromosome at Xp21 and this also escapes X-inactiva-tion. However, there is no evidence of a Y copy of thisgene in humans. We have identified autosomal retro-posons of eIF-2 γ in both humans and mice and an addi-tional retroposon on the X chromosome in somemouse strains. Ark blot analysis of eutherian and meta-therian genomic DNA indicates that X-Y homologuesare present in all species tested except simian pri-mates and kangaroo and that retroposons are com-mon to a wide range of mammals. These results shedlight on the evolution of X-Y homologous genes.INTRODUCTIONGenes controlling the functions of spermatogenesis, Spy (1), andexpression of the male-specific minor transplantation antigenH-Y, Hya, (2) have been mapped to a region of the short arm ofthe mouse Y chromosome (∆Sxr
TL;DR: The present study reports the genetic mapping of the human CYP11B2 gene by radiation hybrid analysis, the isolation of a bacterial artificial chromosome (BAC) containing this gene and its physical mapping by fluorescent in situ hybridization (FISH).
Abstract: Aldosterone synthase (AS) is encoded by the CYP11B2 gene, a candidate for familial hypertension. CYP11B2 was previously mapped to chromosome 8q but its precise localization is necessary for genetic studies of hypertension. The present study reports the genetic mapping of the human CYP11B2 gene by radiation hybrid (RH) analysis, the isolation of a bacterial artificial chromosome (BAC) containing this gene and its physical mapping by fluorescent in situ hybridization (FISH). The CYP11B2 locus is on the most distal segment of the long arm of chromosome 8, proximal to the microsatellite polymorphic marker D8S1704. This location, which was confirmed by FISH, is approximately 60cM telomeric to the currently listed human gene locus (chromosome 8q21-22) and corresponds to cytogenetic band 8q24.3. The BACs containing the gene and a high-resolution map of the CYP11B2 locus are useful for genetic studies of hypertension and other endocrine disorders.
TL;DR: The results raise the possibility that one or more tumor suppressor genes associated with breast cancer may exist at 22q13.1, a new common region of deletion between Interleukin 2 receptor β (IL2RB) and D22S279.
Abstract: Allelic losses on chromosome arm 22q are frequently observed in human meningiomas and in carcinomas of the colon, ovary, and breast. Among 140 primary breast cancers we examined for loss of heterozygosity (LOH) at 16 polymorphic loci on the long arm of chromosome 22, 56 (40%) showed LOH for at least one locus. Eleven of these tumors had retained heterozygosity for markers proximal to the NF2 locus but showed LOH for markers distal to NF2. Deletion mapping indicated a new common region of deletion, 2-cM in extent, at q13.1 between Interleukin 2 receptor beta (IL2RB) and D22S279. Our results raise the possibility that one or more tumor suppressor genes associated with breast cancer may exist at 22q13.1. Comparison of these results with clinicohistological data indicated that allelic losses on 22q tend to occur more frequently in tumors of malignant histological types.
TL;DR: This study provides, for the first time, an in vitro model system of latent HHV‐6 infection whose genome is integrated into host DNA of lymphoma cells that is synergistically enhanced when combined with TPA or n‐butyrate.
Abstract: Human herpesvirus 6 (HHV-6) genome has been found in several human lymphoid malignancies, but configuration of the HHV-6 genome has not been well delineated. We established the HHV-6-positive, Epstein-Barr virus-negative Burkitt's lymphoma cell line Katata. In this study we investigated the status of the HHV-6 genome in Katata cells. Neither linear nor circular HHV-6 DNA was detected by Gardella gel analysis. The fluorescence in situ hybridization technique enabled us to directly visualize the integrated HHV-6 DNA at the single-cell level. Only one integrated site of viral DNA was detected in metaphase chromosomes and it was preferentially located at the long arm of chromosome 22 (22q13). Treatment of the cells with 12-O-tetradecanoyl-phorbol-13-acetate (TPA) or with calcium ionophore A23187 led to induction of the HHV-6 immediate-early gene as well as the late gene. Sodium n-butyrate also gave rise to expression of the HHV-6 genes. The TPA inducibility was synergistically enhanced when combined with A23187 or n-butyrate. Our study provides, for the first time, an in vitro model system of latent HHV-6 infection whose genome is integrated into host DNA of lymphoma cells.
TL;DR: Cytogenetic analyses were performed on 340 follicular thyroid adenomas and goiters after short-term culture and correlated the cytogenetic findings with the histology of the tumors, finding the most impressive correlation was found in the group of lesions with trisomy 7.
TL;DR: The effectiveness and reliability in physically mapping nucleotide sequences on small plant chromosomes achieved by the FISH method using a variety of probes was unequivocally demonstrated.
Abstract: A physical mapping method for unique nucleotide sequences on specific chromosomal regions was developed combining objective chromosome identification and highly sensitive fluorescence in situ hybridisation (FISH). Four unique nucleotide sequences cloned from rice genomic DNAs, varying in size from 1.3 to 400 kb, were mapped on a rice chromosome map. A yeast artificial chromosome (YAC) clone with a 399 kb insert of rice genomic DNA was localised at the distal end of the long arm of rice chromosome (1q2.1) and a bacterial artificial chromosome (BAC) clone (180 kb) containing the rice leaf blast-resistant gene (Pi-b) was shown to occur at the distal end of the long arm of chromosome 2 (2q2.1). A cosmid (35 kb) with the resistance gene (Xa-21) against bacterial leaf blight was mapped on the interstitial region of the long arm on chromosome 11 (11q1.3). Furthermore a single RFLP marker, 1.29 kb in size, was mapped successfully to the distal region of the long arm of rice chromosome 4 (4q2.1). For precise localisation of the nucleotide sequences within the chromosome region, image analyses were effective. The BAC clone was localised to the specific region, 2q2.1:96.16, by image analysis. The result was compared with the known location of the BAC clone on the genetic map and the consistency was confirmed. The effectiveness and reliability in physically mapping nucleotide sequences on small plant chromosomes achieved by the FISH method using a variety of probes was unequivocally demonstrated.
TL;DR: Cytogenetic studies in this series suggest that a region on the long arm of chromosome may be involved in the development and/or progression of ependymomas in children.
Abstract: Cytogenetic and molecular studies of ependymomas have previously demonstrated deletions of chromosomes 17 and 22 as frequent abnormalities, implicating inactivation of tumor suppressor genes in the pathogenesis of these tumors. In the present study, we analyzed 22 childhood ependymomas by standard cytogenetic analysis, fluorescence in situ hybridization (FISH) and polymerase chain reaction (PCR)-based microsatellite analysis of chromosomes 17 and 22. Microsatellite analysis of chromosome 6 was performed to identify submicroscopic deletions implicated by the cytogenetic studies. Among the 22 cases, we demonstrated loss of chromosome 22 in 2 patients, deletion of chromosome 17 in 2 patients, and rearrangements or deletions of chromosome 6 in 5 patients. These data do not suggest that loss of a gene on chromosome 17p plays a primary role in the initiation of pediatric ependymomas. This is in contrast to what has been reported for pediatric CNS primitive neuroectodermal tumors and malignant astrocytomas, in which deletion of 17p is regarded as a primary event. Furthermore, loss of chromosome 22 may define a subset of ependymomas more commonly seen in adults. Cytogenetic studies in this series, however, suggest that a region on the long arm of chromosome may be involved in the development and/or progression of ependymomas in children.
TL;DR: Linkage on chromosome 2 is evaluated of 34 microsatellite markers and an interleukin-1 (IL-1) Taq I polymorphism in 352 U.K. families of type 1 diabetes by multipoint analysis using Mapmaker/Sibs.
Abstract: In the spontaneous mouse model of type 1 diabetes,
the nonobese (NOD) strain, a type 1 diabetes locus,
Idd5 , has been mapped to chromosome 1.
Because mouse chromosome 1 shares a homologous
33-cM region between the genes col3a1 and col6a3 with human chromosome 2q31–q35 (data shown at
http://www.ncbi.nlm.nih.gov/Omim/Homology/), several
groups have searched chromosome 2 for loci affecting
human type 1 diabetes. Previous studies have provided evidence for at least three type 1 diabetes loci ( IDDM7 , IDDM12 , and IDDM13 ) within a 23-cM region of chromosome 2q31–q35. We have now evaluated linkage on chromosome 2, by multipoint
analysis using Mapmaker/Sibs, of 34 microsatellite
markers and an interleukin-1 (IL-1) Taq I polymorphism in 352 U.K. families.
Journal Article•
TL;DR: Analysis of tumor and normal DNAs from 157 meningioma patients using PCR-based polymorphic loci revealed that 1p LOH was associated with chromosome 22 deletions and with abnormalities of the NF2 gene in menedioma, and was shown to be significantly associated with recurrence-free survival.
Abstract: Meningioma is a common tumor of the central nervous system. Dele tions of the short arm of chromosome 1 (Ip) are the second most com monly observed chromosomal abnormality in these tumors. Here, we analyzed tumor and normal DNAs from 157 meningioma patients using PCR-based polymorphic loci. Loss of heterozygosity (LOH) for at least one informative marker on Ip was observed in 54 cases (34%), whereas LOH on Iq occurred in only 9 cases (8%). High-resolution deletion mapping defined a consensus region of deletion flanked distally by D1S2713 and proximally by D1S2134, which spans 1.5 cM within Ip32. LOH in this region has also been observed in several other malignancies, suggesting the presence of a tumor suppressor gene or genes that are important for several types of cancer. Statistical analysis revealed that Ip LOH was associated with chromosome 22 deletions and with abnormali ties of the NF2 gene in meningioma. In addition, unlike other clinical and molecular characteristics, only 1p LOH was shown to be significantly associated with recurrence-free survival.
TL;DR: In this paper, the authors presented methods and reagents for detecting a chromosomal aberration in an animal chromosome or karyotype, where one or more detectably-labeled chromosome-specific probes from a first animal species are hybridized to chromosomes of a second animal species.
Abstract: The invention provides methods and reagents for detecting a chromosomal aberration in an animal chromosome or karyotype. One or more detectably-labeled chromosome-specific probes from a first animal species are hybridized to chromosomes of a second animal species. This results in a banding pattern that can be compared to the pattern found in a normal chromosome or karyotype.
TL;DR: Two children with chromosome 22q11 deletion syndrome who had neuroradiologic evidence of polymicrogyria are reported, and the diagnosis of chromosome 22Q11 deletion should be considered in individuals with poly Microgyria.
Abstract: We report two children with chromosome 22q11 deletion syndrome who had neuroradiologic evidence of polymicrogyria. The diagnosis of chromosome 22q11 deletion should be considered in individuals with polymicrogyria.
TL;DR: A complete sequence-tagged site contig map of chromosome 7, using a library of 3840 clones made in fosmids to promote the stability of repeated DNA, and 34 genes found on chromosome 7 were identified for the first time.
Abstract: As part of the ongoing Candida albicans Genome Project, we have constructed a complete sequence-tagged site contig map of chromosome 7, using a library of 3840 clones made in fosmids to promote the stability of repeated DNA. The map was constructed by hybridizing markers to the library, to a blot of the electrophoretic karyotype, and to a blot of the pulsed-field separation of the SfiI restriction fragments of the genome. The map includes 149 fosmids and was constructed using 79 markers, of which 34 were shown to be genes via determination of function or comparison of the DNA sequence to the public databases. Twenty-five of these genes were identified for the first time. The absolute position of several markers was determined using random breakage mapping. Each of the homologues of chromosome 7 is approximately 1 Mb long; the two differ by about 20 kb. Each contains two major repeat sequences, oriented so that they form an inverted repeat separated by 370 kb of unique DNA. The repeated sequence CARE2/Rel2 is a subtelomeric repeat on chromosome 7 and possibly on the other chromosomes as well. Genes located on chromosome 7 in Candida are found on 12 different chromosomes in Saccharomyces cerevisiae.
Journal Article•
TL;DR: The frequently deleted regions in chromosome 12q in pancreatic cancer that were identified here may provide new avenues for isolating novel tumor suppressor genes.
Abstract: Using the method of microsatellite analysis, we studied 40 tissues with pancreatic ductal adenocarcinoma and identified two commonly deleted regions on the long arm of chromosome 12. One (region A) was found between D12S81 and D12S1719 at 12q21 at a frequency of 67.5%, and the other (region B) was located between D12S360 and D12S78 at 12q22–q23.1 at a frequency of 60%; the latter was reported previously (M. Kimura, et al. Genes Chromosomes Cancer, 17: 88–93, 1996). The results of microsatellite analyses were verified by fluorescence in situ hybridization. We further analyzed 19 pancreatic cancer cell lines by fluorescence in situ hybridization and found that 10 of them showed allelic loss at D12S81 and 6 showed allelic loss at D12S360 . Yeast artificial chromosome contigs were constructed to cover the deleted regions. Region B was completely covered by a 650-kb yeast artificial chromosome clone. The frequently deleted regions in chromosome 12q in pancreatic cancer that were identified here may provide new avenues for isolating novel tumor suppressor genes.
TL;DR: It is concluded that large DNA copy number changes are common in thyroid adenomas, strikingly different from those found in follicular carcinomas consisting of few losses and frequent gains, especially those of chromosome 7.
Abstract: DNA copy number changes were compared in 29 histologically benign follicular adenomas, of which five were atypical, and 13 follicular carcinomas of the thyroid by comparative genomic hybridization. DNA copy number changes were frequent in adenomas (14 out of 29, 48%). Most changes were gains, and they always involved a gain of the entire chromosome 7 (10 out of 29, 34%); other common gains involved chromosomes 5 (28%), 9 (10%), 12 (24%), 14 (21%), 17 (17%), 18 (14%) and X (17%). Losses were found only in four (14%) adenomas. Two of the five atypical adenomas had DNA copy number losses, and none had gains. Unlike adenomas, gains were rare and losses were frequent in carcinomas. A loss of chromosome 22 or 22q was particularly common in carcinomas (6 out of 13, 46%), whereas a loss of chromosome 22 was found in only two (7%) adenomas, one of which was atypical (P = 0.002). A loss of 1p was also frequent in carcinomas (31%), but gains of chromosomes 5, 7, 12, 14 or X that were common in adenomas were not found. Loss of chromosome 22 or 22q was present in six of the eight widely invasive follicular carcinomas, but in only one of the five minimally invasive carcinomas. We conclude that large DNA copy number changes are common in thyroid adenomas. These changes are strikingly different from those found in follicular carcinomas consisting of few losses and frequent gains, especially those of chromosome 7. A loss of chromosome 22 is common in widely invasive follicular carcinoma.
TL;DR: This study focuses on a single large family in whom monosymptomatic primary nocturnal enuresis (PNE) is segregating in three generations and the gene GNAZ has a transducin function in eye and brain and is an obvious candidate gene for PNE.
TL;DR: An efficient method for targeted truncation in the chicken DT40 cells with a high homologous recombination rate is described and it is shown that the predicted truncation at the LIF locus occurred in all of the targeted clones.
Abstract: Truncation of human chromosomes at desired sites by homologous recombination techniques enables functional and structural analyses of human chromosomes and development of human artificial chromosomes. However, this targeted truncation has been inefficient. We describe here an efficient method for targeted truncation in the chicken DT40 cells with a high homologous recombination rate. The human chromosome 22 was transferred into DT40 cells, where human telomeric repeat (TTAGGG)n was targeted to the LIF locus on the chromosome. Molecular and cytogenetic analyses showed that the predicted truncation at the LIF locus occurred in all of the targeted clones.
TL;DR: The organization of olfactory receptor genes on human chromosome 11 is described and characterize by using degenerate PCR-based probes to screen chromosome 11-specific and whole genome clone libraries for members of the OR gene family.
TL;DR: It is concluded that a set of four paralogous 4.1 genes has been evolutionarily conserved in rodents and primates.