In mammals, one of the female X chromosomes and all imprinted genes are expressed exclusively from a single allele in somatic cells. (biomedcentral.com)
However, mono-allelically expressed genes such as imprinted genes, allelically excluded genes, and genes on female X chromosomes replicate asynchronously. (prolekarniky.cz)
Individual chromosomes1
For example, Dr. Harald zur Hausen described an under-condensed appearance of individual chromosomes during mitosis in cell lines derived from 7 different leukemia patients [2] . (prolekarniky.cz)
Homologous chromosomes2
In diploid cells, homologous chromosomes occupy separate territories, but expression from genes located on either the paternal or maternal homolog is usually similar. (biomedcentral.com)
2011]. Sex chromosomes are defined by the presence of a sex-determining region containing a sex-determining factor, and strong selection favors the reduction of recombination in the heterogametic sex between the sex-determining region and nearby sexually antagonistic alleles that have differential fitness effects on males versus females [Bachtrog et al. (karger.com)
Little is known about the three-dimensional (3D) structure of the X chromosomes and of alleles at the imprinted regions. (biomedcentral.com)
Disruption of ASAR6 results in delayed replication, delayed mitotic chromosome condensation, and activation of the previously silent alleles of mono-allelic genes on chromosome 6. (prolekarniky.cz)
Genomic2
MCB probes are established by chromosome microdissection followed by whole genomic DNA amplification. (biomedcentral.com)
Finally, ectopic integration of cloned genomic DNA containing ASAR6 causes delayed replication of entire mouse chromosomes. (prolekarniky.cz)
Cytogenetic1
This created the necessity of generating MCB probes for the chromosomes of other species, potentially interesting from the cytogenetic point of view. (biomedcentral.com)
As MCB probes can unambiguously determine pericentric and paracentric inversions and map the breakpoints, they were immediately recognized to be a useful tool for studying chromosomal evolution. (biomedcentral.com)
In addition, numerous reports have described an abnormal chromosomal phenotype affecting single or a few chromosomes in mitotic preparations from tumor-derived and other established cell lines. (prolekarniky.cz)
Furthermore, the under-condensed and late replicating phenotype present in tumor-derived cells occurred only on certain rearranged chromosomes and not on others, suggesting that the under-condensed and late replicating phenotype was associated with certain chromosomal rearrangements [5] . (prolekarniky.cz)
Species7
Sex chromosomes are fundamental in many species for the development of males or females, including vertebrates, and are known to play an important role in the evolution of sex ratios, sexual selection, sexual dimorphism, and sexual conflict in species with genotypic sex determination (GSD) [Bachtrog et al. (karger.com)
Generation of MCB probes for chromosomes of other species, useful and required in many cytogenetics research fields, was limited by technical difficulties. (biomedcentral.com)
Here we present a complete workflow for MCB probe generation for those cases and species where chromosome morphology is too challenging to recognize target chromosomes by conventional methods and where WCP probes are not available. (biomedcentral.com)
However, application of human MCB probes on chromosomes of evolutionarily distant species is challenging, and often not feasible. (biomedcentral.com)
Mammals1
Growing data from non-model organisms are changing our understanding of sex chromosome evolution by challenging theoretical paradigms derived mostly from comparative karyotypic research on organisms with well-differentiated sex chromosomes, such as insects, mammals, and birds [Bachtrog et al. (karger.com)
Genes1
In contrast, X-linked genes are subject to silencing by X chromosome inactivation (XCI) on one of the two homologs in female somatic cells [ 2 ], and a subset of autosomal genes are subject to imprinting and expressed from either the paternal or maternal allele [ 3 ]. (biomedcentral.com)
By applying a novel Hi-C method to map allelic chromatin contacts, we discover a specific bipartite organization of the mouse inactive X chromosome that probably plays an important role in maintenance of gene silencing. (biomedcentral.com)
We have identified a cis -acting locus on human chromosome 6 that controls this replication-timing program. (prolekarniky.cz)
Include1
Approaches to visualize the 3D configuration of the whole nucleus and of entire chromosomes include Hi-C, a method to identify chromatin contacts within chromosomes (intrachromosomal) or between chromosomes (interchromosomal). (biomedcentral.com)
Entire1
2 hour delay in both the initiation and the completion of DNA synthesis along the entire length of the chromosome [5] . (prolekarniky.cz)
Single1
Similarities were found between ESU and E. macquarii (EMA), such as identical chromosome number (2n = 50), a single and dimorphic nucleolus organizer region (NOR) localized in a microchromosome pair (ESU14) of both sexes (detected via FISH of 18S rDNA). (karger.com)
Extremely1
The individual under-condensed chromosomes synthesized DNA after the normally condensed chromosomes had finished replication, indicating that the under-condensed chromosomes were extremely late replicating, with DNA synthesis extending into the G2 phase. (prolekarniky.cz)
Evolution2
2012]. Current models of sex chromosome evolution propose that sex chromosomes originate from autosomes [Charlesworth and Charlesworth, 2000] and have done so multiple times independently in diverse lineages across the tree of life [Bachtrog et al. (karger.com)
2011]. Thus, the discovery of additional sex chromosome systems is critical if we are to decipher the evolution of sex-determining mechanisms and associated traits [The Tree of Sex Consortium et al. (karger.com)
Identify2
The workflow was successfully applied for murine chromosomes that are difficult to identify unambiguously. (biomedcentral.com)
The absolutely necessary condition for chromosome microdissection is the possibility to identify the target chromosome unambiguously. (biomedcentral.com)
Cells2
The heterochromatization of one of the X chromosomes in female somatic cells is initiated by the long non-coding RNA (lncRNA) Xist that coats the Xi in early embryogenesis and silences transcription by recruiting specific proteins that put in place repressive histone modifications such as tri-methylation of histone H3K27, ubiquitination of histone H2AK119, and de-acetylation [ 9 - 12 ]. (biomedcentral.com)
Morphological differences between mitotic chromosomes residing within the same cell were first described in mammalian cells over forty years ago (reviewed in [1] ). (prolekarniky.cz)
Specific2
This was partly due to technical difficulties in generating region specific DNA libraries/probes to be incorporated into mcb probe mixes. (biomedcentral.com)
Chromosomes occupy specific territories within the nucleus [ 1 ]. (biomedcentral.com)