Deletion of a telomeric region on chromosome 8 correlates with higher productivity and stability of CHO cell lines.

Chinese Hamster Ovary (CHO) cells are widely used for large scale production of recombinant biopharmaceuticals. Although these cells have been extensively used, a demand to further increase the performance, for example, to facilitate the process of clone selection to isolate the highest producing cell lines that maintain stability of production over time is still existing. We compared gene expression profiles of high versus low producing CHO clones to identify regulated genes which can be used as biomarkers during clone selection or for cell line engineering.

Praomys tullbergi (Muridae, Rodentia) genome architecture decoded by comparative chromosome painting with Mus and Rattus.

The order Rodentia and in particular the Muridae are characterised by extremely high rates of chromosome evolution and remarkable chromosome diversity. The Praomys group (Murinae, Muridae and Rodentia) constitutes a diverse and abundant group divided into two complexes, the jacksoni complex and the tullbergi complex which includes the species Praomys tullbergi. Comparative chromosome painting using the two index genomes, Mus musculus and Rattus norvegicus, was performed resulting in a high resolution chromosome map for P.

Gain of chromosome band 7q11 in papillary thyroid carcinomas of young patients is associated with exposure to low-dose irradiation.

The main consequence of the Chernobyl accident has been an increase in papillary thyroid carcinomas (PTCs) in those exposed to radioactive fallout as young children. Our aim was to identify genomic alterations that are associated with exposure to radiation. We used array comparative genomic hybridization to analyze a main (n = 52) and a validation cohort (n = 28) of PTC from patients aged <25 y at operation and matched for age at diagnosis and residency.

Novel gene rearrangements in transformed breast cells identified by high-resolution breakpoint analysis of chromosomal aberrations.

Chromosomal copy number alterations and chromosomal rearrangements are frequent mutations in human cancer. Unlike copy number alterations, little is known about the role and occurrence of chromosomal rearrangements in breast cancer. This may be due to the fact that chromosome-based breakpoint analysis is widely restricted to cultured cells.

Analysis of Pax6 contiguous gene deletions in the mouse, Mus musculus, identifies regions distinct from Pax6 responsible for extreme small-eye and belly-spotting phenotypes.

In the mouse Pax6 function is critical in a dose-dependent manner for proper eye development. Pax6 contiguous gene deletions were shown to be homozygous lethal at an early embryonic stage. Heterozygotes express belly spotting and extreme microphthalmia.

Chromosomal changes characterize head and neck cancer with poor prognosis.

It is well established that genetic alterations may be associated to prognosis in tumor patients. This study investigates chromosomal changes that predict the clinical outcome of head and neck squamous cell carcinoma (HNSCC) and correlate to characteristic clinicopathological parameters. We applied comparative genomic hybridization (CGH) to tissue samples from 117 HNSCC patients scheduled for radiotherapy.

A high-resolution map of synteny disruptions in gibbon and human genomes.

Gibbons are part of the same superfamily (Hominoidea) as humans and great apes, but their karyotype has diverged faster from the common hominoid ancestor. At least 24 major chromosome rearrangements are required to convert the presumed ancestral karyotype of gibbons into that of the hominoid ancestor. Up to 28 additional rearrangements distinguish the various living species from the common gibbon ancestor.

Identification, characterization and clinical implications of two markers detected at prenatal diagnosis.

Objectives: Marker chromosomes are relatively rare in the general population as its identification at prenatal diagnosis. In this article, we identified and characterized two de novo supernumerary marker chromosomes in a mosaic form at prenatal diagnosis.

Methods: The two cases presented were detected during prenatal diagnosis at 17 and 15 weeks of gestation.

High-resolution comparative chromosome painting in the Arizona collared peccary (Pecari tajacu, Tayassuidae): a comparison with the karyotype of pig and sheep.

We used chromosome painting with chromosome-specific probes derived from domestic sheep and pig for a high-resolution cytogenetic comparison with the karyotype of collared peccary (Pecari tajacu sonoriensis). A reorganization of the karyotype involving at least 62-66 conserved segments were observed between the sheep and collared peccary. This is an extremely high number compared with other members of the same mammalian order (Cetartiodactyla).

Chromosome reshuffling in birds of prey: the karyotype of the world's largest eagle (Harpy eagle, Harpia harpyja) compared to that of the chicken (Gallus gallus).

Like various other diurnal birds of prey, the world's largest eagle, the Harpy (Harpia harpyja), presents an atypical bird karyotype with 2n=58 chromosomes. There is little knowledge about the dramatic changes in the genomic reorganization of these species compared to other birds. Since recently, the chicken provides a "default map" for various birds including the first genomic DNA sequence of a bird species.

The evolution of eutherian chromosomes.

The gross organization of the genome of Eutheria (placental mammals) into chromosomes follows a simple architecture that, with some minor changes, is almost completely conserved for more than 100 million years in various species of almost all extant mammalian orders. Recent molecular cytogenetic results--especially those from the assumed oldest clade, the Afrotheria--suggest an ancestral karyotype that would calculate the "default" frequency of gross rearrangements to less than two changes within 10 million years of mammalian evolution. The main changes are the fission, movement and subsequent fusion of large chromosome segments or of chromosome arms.

The evolutionary history of human chromosome 7.

We report on a comparative molecular cytogenetic and in silico study on evolutionary changes in human chromosome 7 homologs in all major primate lineages. The ancestral mammalian homologs comprise two chromosomes (7a and 7b/16p) and are conserved in carnivores. The subchromosomal organization of the ancestral primate segment 7a shared by a lemur and higher Old World monkeys is the result of a paracentric inversion.

Multidirectional chromosome painting between the Hirola antelope (Damaliscus hunteri, Alcelaphini, Bovidae), sheep and human.

Chromosome specific painting probes of human, sheep and the Hirola antelope ( Damaliscus hunteri ) derived by flow sorting of chromosomes were used in multi directional chromosome painting experiments to better define the karyological relationship within Bovidae species (specifically, Caprini and Alcelaphini tribes) and humans. Although not all chromosomes of Damaliscus hunteri could be resolved into single peaks by flow-sorting we managed to present a complete homology map for chromosomes between the three species. When comparing the karyotype of Damaliscus hunteri with human all of the main known motives in mammalian chromosome evolution are present (i.

Molecular cytogenetic analysis and centromeric satellite organization of a novel 8;11 translocation in sheep: a possible intermediate in biarmed chromosome evolution.

During analysis of genome organization in sheep (Ovis aries, 2n = 54, XY/XX), we found a novel chromosomal translocation in an animal expected to be normal, adding to the six 'centric fusions' previously reported. The translocation was identified as t(8;11) by G-banding and was shown to be centric, involving whole chromosome arms by chromosome painting with probes for Chromosomes (Chrs) 8 and 11. Satellite I and a newly isolated satellite II clone was used to characterize the centromeric regions of both the novel and the three pairs of evolutionarily derived biarmed chromosomes.

A nonredundant multicolor bar code as a screening tool for rearrangements in neoplasia.

A chromosome bar code describes the colored pattern of chromosome segments and is derived by multicolor fluorescence in situ hybridization (FISH) of defined molecular probes. Published approaches to the simultaneous differentiation of whole karyotypes with bar codes have not allowed the unequivocal identification of all chromosome segments because of color redundancy of the patterns from a multitude of identically colored segments. Here, we present a chromosome bar code approach in which the problem of color redundancy has been overcome.

Chromosomal phylogeny and evolution of gibbons (Hylobatidae).

Although human and gibbons are classified in the same primate superfamily (Hominoidae), their karyotypes differ by extensive chromosome reshuffling. To date, there is still limited understanding of the events that shaped extant gibbon karyotypes. Further, the phylogeny and evolution of the twelve or more extant gibbon species (lesser apes, Hylobatidae) is poorly understood, and conflicting phylogenies have been published.

Towards the delineation of the ancestral eutherian genome organization: comparative genome maps of human and the African elephant (Loxodonta africana) generated by chromosome painting.

This study presents a whole-genome comparison of human and a representative of the Afrotherian clade, the African elephant, generated by reciprocal Zoo-FISH. An analysis of Afrotheria genomes is of special interest, because recent DNA sequence comparisons identify them as the oldest placental mammalian clade. Complete sets of whole-chromosome specific painting probes for the African elephant and human were constructed by degenerate oligonucleotide-primed PCR amplification of flow-sorted chromosomes.

The phylogeny of howler monkeys (Alouatta, Platyrrhini): reconstruction by multicolor cross-species chromosome painting.

We performed multidirectional chromosome painting in a comparative cytogenetic study of the three howler monkey species Alouatta fusca, A. caraya and A. seniculus macconnelli (Atelinae, Platyrrhini) in order to reconstruct phylogenetic relationships within this genus.

Male mouse recombination maps for each autosome identified by chromosome painting.

Linkage maps constructed from genetic analysis of gene order and crossover frequency provide few clues to the basis of genomewide distribution of meiotic recombination, such as chromosome structure, that influences meiotic recombination. To bridge this gap, we have generated the first cytological recombination map that identifies individual autosomes in the male mouse. We prepared meiotic chromosome (synaptonemal complex [SC]) spreads from 110 mouse spermatocytes, identified each autosome by multicolor fluorescence in situ hybridization of chromosome-specific DNA libraries, and mapped >2,000 sites of recombination along individual autosomes, using immunolocalization of MLH1, a mismatch repair protein that marks crossover sites.

Towards unlimited colors for fluorescence in-situ hybridization (FISH).

We describe a FISH protocol that allows rehybridization of complex DNA probes up to four times to the same specimen. This strategy, which we termed ReFISH, opens a wide range of new applications to conventional band pass filter epifluorescence microscopy. These include M-FISH karyotyping and cross-species color banding that emulate multiplex probe sets labeled with up to 12 fluorochromes in sequential hybridizations to the same specimen.