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Cytogenetic and Genome Research 01/2013; 138(2-4):377-384. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2013; 138(2-4):377-384. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2013; 138(2-4):69-83. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):69-84. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):254-340. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):165-253. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):377-84. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):369-76. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):157-64. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):341-67. · 1.53 Impact Factor
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Cytogenetic and Genome Research 01/2012; 138(2-4):85-156. · 1.53 Impact Factor
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Cytogenetic and Genome Research 10/2010; 130-131(1-8):1-568. · 1.53 Impact Factor
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Insights into vertebrate cytogenetics. Cytogenet Genome Res. 01/2010; 130:1-568.
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ABSTRACT: The chromosomal distribution of the conserved vertebrate telomeric (TTAGGG)(n) sequence was studied by fluorescence in situ hybridization (FISH) in four Xenopus species and the triploid Silurana tropicalis. As expected, hybridization signals were observed at the distal ends of every chromosome in all species. In addition, the hybridization pattern demonstrates varied organization of (TTAGGG)(n) sequences in the different karyotypes. In X. borealis and X. muelleri hybridization signals intensely labeled one end of a homologous chromosome pair that coincides with the sites containing ribosomal RNA gene clusters. The karyotype of X. clivii remarkably differs from other Xenopus karyotypes in displaying numerous interstitial telomeric sites (ITS). C-banding analysis shows that the non-telomeric sites appear to correspond to the interstitially located constitutive heterochromatin. This suggests that interstitial telomeric sites in X. clivii do not necessarily represent the relic of ancestral telomeres resulting from the fusion of chromosomes, but their occurrence is due to the fact that (TTAGGG)(n) repeat arrays may be a constituent of highly repetitive DNA.
Cytogenetic and Genome Research 02/2008; 122(3-4):396-400. · 1.53 Impact Factor
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ABSTRACT: We report the finding of the first haploid-diploid-triploid mosaic fish from the family Poeciliidae. The animal was derived from a laboratory cross of a female F1 hybrid of Poecilia mexicana and P. latipinna with a male from an ornamental strain derived from P. mexicana and P. sphenops (Black molly). It was identified because of its unusual pigmentation pattern and molecular methods (flow cytometry, NOR staining) confirmed its mosaic genotype. The mode of mosaic formation and the possible importance for poeciliid fish evolution are discussed.
Cytogenetic and Genome Research 02/2007; 119(1-2):131-4. · 1.53 Impact Factor
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R Melcher,
O Al-Taie,
T Kudlich,
E Hartmann,
S Maisch, C Steinlein,
M Schmid,
A Rosenwald,
T Menzel,
W Scheppach,
H Luhrs
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ABSTRACT: In this study nine colorectal cancer cell lines were analysed by 10K SNP-arrays and spectral karyotyping (SKY). Complex chromosomal alterations and breakpoints of deleted or translocated fragments found by SKY could further be characterized by SNP-array analysis. Interestingly many monoallelic regions identified by SNP-array analysis display no copy number alterations, representing uniparental disomy (UPD). It was demonstrated that UPD seems to be involved in activation of early-acting tumor suppressor genes in MSS- (APC, CDKN2A) and MSI- (MLH1, MSH2, APC, CDKN2A) colorectal cancer cell lines. Genes involved later on in the adenoma-carcinoma sequence (i.e. TP53/SMAD4) were not found to be inactivated by UPD. Furthermore, identified amplified monoallelic regions may include oncogenes activated by allele-specific-amplification (i.e. Cyclin D1). However, at present, the majority of the monoallelic regions located in the present study have not yet been associated with known tumor suppressor genes and oncogenes. Further studies are warranted to identify relevant genes in the respective regions and to further verify the results presented here.
Cytogenetic and Genome Research 02/2007; 118(2-4):214-21. · 1.53 Impact Factor
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K Neveling,
R Kalb,
A R Florl,
S Herterich,
R Friedl,
H Hoehn,
C Hader,
F H Hartmann,
I Nanda, C Steinlein,
M Schmid,
H Tonnies,
C D Hurst,
M A Knowles,
H Hanenberg,
W A Schulz,
D Schindler
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ABSTRACT: Bladder carcinomas frequently show extensive deletions of chromosomes 9p and/or 9q, potentially including the loci of the Fanconi anemia (FA) genes FANCC and FANCG. FA is a rare recessive disease due to defects in anyone of 13 FANC genes manifesting with genetic instability and increased risk of neoplasia. FA cells are hypersensitive towards DNA crosslinking agents such as mitomycin C and cisplatin that are commonly employed in the chemotherapy of bladder cancers. These observations suggest the possibility of disruption of the FA/BRCA DNA repair pathway in bladder tumors. However, mutations in FANCC or FANCG could not be detected in any of 23 bladder carcinoma cell lines and ten surgical tumor specimens by LOH analysis or by FANCD2 immunoblotting assessing proficiency of the pathway. Only a single cell line, BFTC909, proved defective for FANCD2 monoubiquitination and was highly sensitive towards mitomycin C. This increased sensitivity was restored specifically by transfer of the FANCF gene. Sequencing of FANCF in BFTC909 failed to identify mutations, but methylation of cytosine residues in the FANCF promoter region was demonstrated by methylation-specific PCR, HpaII restriction and bisulfite DNA sequencing. Methylation-specific PCR uncovered only a single instance of FANCF promoter hypermethylation in surgical specimens of further 41 bladder carcinomas. These low proportions suggest that in contrast to other types of tumors silencing of FANCF is a rare event in bladder cancer and that an intact FA/BRCA pathway might be advantageous for tumor progression.
Cytogenetic and Genome Research 02/2007; 118(2-4):166-76. · 1.53 Impact Factor
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ABSTRACT: Some of the largest B chromosomes so far discovered in vertebrates are present in the cyprinid fish Alburnus alburnus. Previous cytogenetic analyses revealed a diploid chromosome number of 2n = 50. In addition, in some individuals one or two unusually large B chromosomes are present. Two morphologically different types of B chromosomes were observed. The frequency of animals bearing a supernumerary chromosome was found to vary considerably between different populations. A more detailed analysis of the A and B chromosomes of A. alburnus by conventional banding techniques, as well as fluorescence in-situ hybridization (FISH) with the telomeric DNA repeats (GGGTTA)7/(TAACCC)7, 18S + 28S rDNA and 5S rDNA were performed in the present study. Furthermore, a B chromosome-specific DNA probe obtained by amplified length polymorphism (AFLP) was hybridized on metaphases of A. alburnus carrying supernumerary B chromosomes. The banding analyses showed that the B chromosomes are completely heterochromatic, consist of GC-rich DNA sequences, replicate their DNA in the very late S-phase of the cell cycle and are composed mainly of a specific retrotransposable DNA element. Finally, blood probes from A. alburnus were collected for DNA-flow cytometric measurements. It could be shown that the huge supernumerary chromosomes represent nearly 10% of the total genome size of A. alburnus.
Chromosome Research 02/2006; 14(3):231-42. · 3.09 Impact Factor
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ABSTRACT: Cytogenetic chromosome analysis by classical G-banding was supplemented by spectral karyotyping (SKY) in 12 cases of diffuse large B-cell lymphoma (DLBL). SKY is a fluorescence in-situ-based, genome-wide screening technique allowing identification of genetic material even in highly condensed metaphase chromosomes of poor morphology. By simultaneous hybridization of whole chromosome painting probes onto tumor chromosome spreads genetic rearrangements are visualized permitting the clarification of even complex karyotype alterations and the identification of genetic material of previously unknown origin, so-called marker chromosomes. Taking the SKY results into account, we reevaluated the G-banding karyotypes initially carried out, thus generating a more precise karyotype in ten of twelve (83%) cases investigated. In particular, thirteen chromosomal rearrangements not correctly recognized by classical cytogenetics were identified, the genetic origin of seven marker chromosomes was elucidated and three structural genetic rearrangements were redefined. We found SKY to be a valuable technique to establish a definite karyotype in addition to classical cytogenetics.
Cytogenetic and Genome Research 02/2006; 114(3-4):274-8. · 1.53 Impact Factor
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ABSTRACT: We describe a 3-year-old girl with severe delays in mental and motor skills, a history of generalized seizures, and subtle dysmorphic features. Conventional cytogenetics revealed a mosaic karyotype. A de novo ectopic NOR at the telomeric region of the short arm of one chromosome 8 (8ps) was found in 90% of lymphocyte and in 98% of fibroblast metaphases. A small NOR-bearing marker chromosome and a large derivative chromosome 8 without short arm satellites (der(8)) were present in the remaining cells. FISH with a probe specific for centromeres 14 and 22 labeled both the telomeric region of 8ps and the small marker centromere. Der(8) included an inverted duplication of 8p and a rearranged duplication of 8q but lacked a second centromere. A subtelomeric probe for 8p revealed a cryptic deletion in 8ps and der(8). Thus, the karyotype represents a combination of submicroscopic partial monosomy 8pter and mosaic trisomy 8.
Cytogenetic and Genome Research 02/2004; 106(1):55-60. · 1.53 Impact Factor
