• MeSH
• buněčné jádro genetika   MeSH
• centromera genetika   MeSH
• chromozom X genetika   MeSH
• dystrofin genetika   MeSH
• kultivované buňky MeSH
• lymfocyty cytologie   mikrobiologie   MeSH

• MeSH
• apoptóza MeSH
• buňky K562 MeSH
• centromera MeSH
• chromozomální aberace MeSH
• fluorescence MeSH
• fragmentace DNA MeSH
• hybridizace in situ MeSH
• lidé MeSH
• Check Tag
• lidé MeSH

Loss of totipotentcy in an early embryo is directed by molecular processes responsible for cell fate decisions. Three dimensional genome organisation is an important factor linking chromatin architecture with stage specific gene expression patterns. Little is known about the role of chromosome organisation in gene expression regulation of lineage specific factors in mammalian embryos. Using bovine embryos as a model we have described these interactions at key developmental stages. Three bovine chromosomes (BTA) that differ in size, number of carried genes, and contain loci for key lineage regulators OCT4, NANOG and CDX2, were investigated. The results suggest that large chromosomes regardless of their gene density (BTA12 gene-poor, BTA5 gene-rich) do not significantly change their radial position within the nucleus. Gene loci however, may change its position within the chromosome territory (CT) and relocate its periphery, when stage specific process of gene activation is required. Trophectoderm specific CDX2 and epiblast precursor NANOG loci tend to locate on the surface or outside of the CTs, at stages related with their high expression. We postulate that the observed changes in CT shape reflect global alternations in gene expression related to differentiation.

• MeSH
• buněčné jádro genetika   MeSH
• buněčný rodokmen MeSH
• embryonální vývoj MeSH
• hybridizace in situ fluorescenční MeSH
• nanog genetika   metabolismus   MeSH
• oktamerní transkripční faktor 3 genetika   metabolismus   MeSH
• savčí chromozomy genetika   MeSH
• skot MeSH
• transkripční faktor CDX2 genetika   metabolismus   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Recurring chromosomal abnormalities are associated with specific tumour types. The EWSR1 and FLI1 genes are involved in balanced translocation t(11;22)(q24;q12), which is present in more than 85% of Ewing sarcomas. In our previous study, we have found that the fusion genes pertaining to both derivative chromosomes 11 and 22 in Ewing sarcoma cell nuclei are shifted to the midway nuclear position between the native EWSR1 and FLI1 genes. In this contribution we focused our attention at nuclear positioning of other genetic elements of chromosomes 11 and 22 in order to find if the whole derivative chromosomes or only their translocated parts change their nuclear positions in comparison with the native chromosomes. Using repeated fluorescence in situ hybridization and high-resolution cytometry, 2D radial positions of EWSR1, BCR, FLI1, BCL1 genes and fluorescence weight centres of chromosome territories were compared for intact and derivative chromosomes 11 and 22 in nuclei of three Ewing sarcoma samples. Significant radial shift was obtained for the derivative EWSR1, FLI1 and BCL1 genes and for the derivative chromosome 11 compared with the intact ones and not very significant for chromosome 22 and the BCR gene. Our results also suggest that the mean nuclear positions of fusion genes are determined by the final structure of the derivative chromosomes and do not depend on the location of the translocation event.

• MeSH
• buněčné jádro genetika   MeSH
• chromozomální aberace MeSH
• Ewingův sarkom genetika   patologie   MeSH
• financování organizované MeSH
• genová dávka MeSH
• hybridizace in situ fluorescenční MeSH
• lidé MeSH
• lidské chromozomy, pár 11 MeSH
• lidské chromozomy, pár 22 MeSH
• lymfocyty cytologie   MeSH
• nádory kostní tkáně genetika   patologie   MeSH
• pravděpodobnost MeSH
• proteiny vázající kalmodulin fyziologie   genetika   MeSH
• proteiny vázající RNA fyziologie   genetika   MeSH
• protoonkogenní protein c-fli-1 fyziologie   genetika   MeSH
• sekvenční homologie nukleových kyselin MeSH
• translokace genetická MeSH
• velikost buňky MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• srovnávací studie MeSH

Chromosome painting (CP) refers to visualization of large chromosome regions, entire chromosome arms, or entire chromosomes via fluorescence in situ hybridization (FISH). For CP in plants, contigs of chromosome-specific bacterial artificial chromosomes (BAC) from the target species or from a closely related species (comparative chromosome painting, CCP) are typically applied as painting probes. Extended pachytene chromosomes provide the highest resolution of CP in plants. CP enables identification and tracing of particular chromosome regions and/or entire chromosomes throughout all meiotic stages as well as corresponding chromosome territories in premeiotic interphase nuclei. Meiotic pairing and structural chromosome rearrangements (typically inversions and translocations) can be identified by CP. Here, we describe step-by-step protocols of CP and CCP in plant species including chromosome preparation, BAC DNA labeling, and multicolor FISH.

• MeSH
• chromozomy rostlin * MeSH
• hybridizace in situ fluorescenční metody   MeSH
• malování chromozomů metody   MeSH
• meióza genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Human embryonic stem cells (hES) are unique in their pluripotency and capacity for self-renewal. Therefore, we have studied the differences in the level of chromatin condensation in pluripotent and all-trans retinoic acid-differentiated hES cells. Nuclear patterns of the Oct4 (6p21.33) gene, responsible for hES cell pluripotency, the C-myc (8q24.21) gene, which controls cell cycle progression, and HP1 protein (heterochromatin protein 1) were investigated in these cells. Unlike differentiated hES cells, pluripotent hES cell populations were characterized by a high level of decondensation for the territories of both chromosomes 6 (HSA6) and 8 (HSA8). The Oct4 genes were located on greatly extended chromatin loops in pluripotent hES cell nuclei, outside their respective chromosome territories. However, this phenomenon was not observed for the Oct4 gene in differentiated hES cells, for the C-myc gene in the cell types studied. The high level of chromatin decondensation in hES cells also influenced the nuclear distribution of all the variants of HP1 protein, particularly HP1 alpha, which did not form distinct foci, as usually observed in most other cell types. Our experiments showed that unlike C-myc, the Oct4 gene and HP1 proteins undergo a high level of decondensation in hES cells. Therefore, these structures seem to be primarily responsible for hES cell pluripotency due to their accessibility to regulatory molecules. Differentiated hES cells were characterized by a significantly different nuclear arrangement of the structures studied.

• MeSH
• buněčná diferenciace genetika   účinky léků   MeSH
• buněčné jádro genetika   ultrastruktura   MeSH
• buněčné linie MeSH
• chromozomální proteiny, nehistonové genetika   metabolismus   MeSH
• embryonální kmenové buňky metabolismus   ultrastruktura   MeSH
• financování organizované MeSH
• lidé MeSH
• pluripotentní kmenové buňky metabolismus   ultrastruktura   MeSH
• restrukturace chromatinu MeSH
• signální transdukce genetika   MeSH
• trans-aktivátory metabolismus   účinky léků   MeSH
• tretinoin MeSH
• vazebná místa genetika   MeSH
• Check Tag
• lidé MeSH

The Neotropical monophyletic catfish genus Harttia represents an excellent model to study karyotype and sex chromosome evolution in teleosts. Its species split into three phylogenetic clades distributed along the Brazilian territory and they differ widely in karyotype traits, including the presence of standard or multiple sex chromosome systems in some members. Here, we investigate the chromosomal rearrangements and associated synteny blocks involved in the origin of a multiple X1X2Y sex chromosome system present in three out of six sampled Amazonian-clade species. Using 5S and 18S ribosomal DNA fluorescence in situ hybridization and whole chromosome painting with probes corresponding to X1 and X2 chromosomes of X1X2Y system from H. punctata, we confirm previous assumptions that X1X2Y sex chromosome systems of H. punctata, H. duriventris and H. villasboas represent the same linkage groups which also form the putative XY sex chromosomes of H. rondoni. The shared homeology between X1X2Y sex chromosomes suggests they might have originated once in the common ancestor of these closely related species. A joint arrangement of mapped H. punctata X1 and X2 sex chromosomes in early diverging species of different Harttia clades suggests that the X1X2Y sex chromosome system may have formed through an X chromosome fission rather than previously proposed Y-autosome fusion.

• MeSH
• chromozom Y MeSH
• fylogeneze MeSH
• hybridizace in situ fluorescenční MeSH
• pohlavní chromozomy genetika   MeSH
• sumci * genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• buněčné jádro genetika   MeSH
• chromozomy genetika   MeSH
• finanční podpora výzkumu jako téma MeSH
• lidé MeSH
• lymfocyty fyziologie   MeSH
• telomery genetika   ultrastruktura   MeSH
• Check Tag
• lidé MeSH

• MeSH
• bcr-abl fúzové proteiny genetika   MeSH
• cyklin D1 genetika   MeSH
• DNA vazebné proteiny genetika   MeSH
• Ewingův sarkom genetika   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• lidé MeSH
• lidské chromozomy, pár 11 genetika   MeSH
• lidské chromozomy, pár 22 genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• srovnávací studie MeSH

During interphase, the chromosomes of eukaryotes decondense and they occupy distinct regions of the nucleus, called chromosome domains or chromosome territories (CTs). In plants, the Rabl's configuration, with telomeres at one pole of nucleus and centromeres at the other, appears to be common, at least in plants with large genomes. It is unclear whether individual chromosomes of plants adopt defined, genetically determined addresses within the nucleus, as is the case in mammals. In this study, the nuclear disposition of alien rye and barley chromosomes and chromosome arm introgressions into wheat while using 3D-FISH in various somatic tissues was analyzed. All of the introgressed chromosomes showed Rabl's orientation, but their relative positions in the nuclei were less clear. While in most cases pairs of introgressed chromosomes occupied discrete positions, their association (proximity) along their entire lengths was rare, and partial association only marginally more frequent. This arrangement is relatively stable in various tissues and during various stages of the cell cycle. On the other hand, the length of a chromosome arm appears to play a role in its positioning in a nucleus: shorter chromosomes or chromosome arms tend to be located closer to the centre of the nucleus, while longer arms are more often positioned at the nuclear periphery.

• MeSH
• buněčné jádro MeSH
• chromatin genetika   MeSH
• chromozomy rostlin * MeSH
• hybridizace in situ fluorescenční * metody   MeSH
• interfáze * genetika   MeSH
• ječmen (rod) genetika   MeSH
• počítačové zpracování obrazu MeSH
• průtoková cytometrie MeSH
• pšenice genetika   MeSH
• žito genetika   MeSH
• Publikační typ
• časopisecké články MeSH