The architecture of chicken chromosome territories changes during differentiation

Background  

Between cell divisions the chromatin fiber of each chromosome is restricted to a subvolume of the interphase cell nucleus called chromosome territory. The internal organization of these chromosome territories is still largely unknown.     

Structure and evolution of <Emphasis Type="Italic">Apetala3</Emphasis>, a sex-linked gene in <Emphasis Type="Italic">Silene latifolia</Emphasis>

Background  

The evolution of sex chromosomes is often accompanied by gene or chromosome rearrangements. Recently, the gene AP3 was characterized in the dioecious plant species Silene latifolia. It was suggested that this gene had been transferred from an autosome to the Y chromosome.     

Polyploidization increases meiotic recombination frequency in <Emphasis Type="Italic">Arabidopsis</Emphasis>

Background  

Polyploidization is the multiplication of the whole chromosome complement and has occurred frequently in vascular plants. Maintenance of stable polyploid state over generations requires special mechanisms to control pairing and distribution of more than two homologous chromosomes during meiosis. Since a minimal number of crossover events is essential for correct chromosome segregation, we investigated whether polyploidy has an influence on the frequency of meiotic recombination.     

Genomic transcriptional response to loss of chromosomal supercoiling in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Background  

The chromosome of Escherichia coli is maintained in a negatively supercoiled state, and supercoiling levels are affected by growth phase and a variety of environmental stimuli. In turn, supercoiling influences local DNA structure and can affect gene expression. We used microarrays representing nearly the entire genome of Escherichia coli MG1655 to examine the dynamics of chromosome structure.     

Polytene chromosomes as indicators of phylogeny in several species groups of Drosophila

Background  

Polytene chromosome banding patterns have long been used by Drosophila evolutionists to infer degree of relatedness among taxa. Recently, nucleotide sequences have preempted this traditional method. We place the classical Drosophila evolutionary biology tools of polytene chromosome inversion analysis in a phylogenetic context and assess their utility in comparison to nucleotide sequences.     

Gene expression analysis indicates extensive genotype-specific crosstalk between the conjugative F-plasmid and the E. coli chromosome

Background  

Plasmids are an important component of the bacterial genome, but the crosstalk between genes encoded on the chromosome and on the plasmid is still poorly understood.     

Paternal imprinting of the SLC22A1LS gene located in the human chromosome segment 11p15.5

Background  

Genomic imprinting is an epigenetic chromosomal modification in the gametes or zygotes that results in a non-random monoallelic expression of specific autosomal genes depending upon their parent of origin. Approximately 44 human genes have been reported to be imprinted. A majority of them are clustered, including some on chromosome segment 11p15.5. We report here the imprinting status of the SLC22A1LS gene from the human chromosome segment 11p15.5     

A necdin/MAGE-like gene in the chromosome 15 autism susceptibility region: expression, imprinting, and mapping of the human and mouse orthologues

Background  

Proximal chromosome 15q is implicated in neurodevelopmental disorders including Prader-Willi and Angelman syndromes, autistic disorder and developmental abnormalities resulting from chromosomal deletions or duplications. A subset of genes in this region are subject to genomic imprinting, the expression of the gene from only one parental allele.     

Neo-sex chromosomes in the black muntjac recapitulate incipient evolution of mammalian sex chromosomes

Background  

The regular mammalian X and Y chromosomes diverged from each other at least 166 to 148 million years ago, leaving few traces of their early evolution, including degeneration of the Y chromosome and evolution of dosage compensation.     

Few alterations in clinical pathology and histopathology observed in a CYP2C18&;19 humanized mice model

Background  

This study was performed to characterize a gene-addition transgenic mouse containing a BAC (bacterial artificial chromosome) clone spanning the human CYP2C18&19 genes (tg-CYP2C18&19).     

The evolution of imprinting: chromosomal mapping of orthologues of mammalian imprinted domains in monotreme and marsupial mammals

Background  

The evolution of genomic imprinting, the parental-origin specific expression of genes, is the subject of much debate. There are several theories to account for how the mechanism evolved including the hypothesis that it was driven by the evolution of X-inactivation, or that it arose from an ancestrally imprinted chromosome.     

Genetic conflict outweighs heterogametic incompatibility in the mouse hybrid zone?

Background  

The Mus musculus musculus/M. m. domesticus contact zone in Europe is characterised by sharp frequency discontinuities for sex chromosome markers at the centre of wider clines in allozyme frequencies.     

High cell density and latent membrane protein 1 expression induce cleavage of the mixed lineage leukemia gene at 11q23 in nasopharyngeal carcinoma cell line

Background  

Nasopharyngeal carcinoma (NPC) is commonly found in Southern China and South East Asia. Epstein-Barr virus (EBV) infection is well associated with NPC and has been implicated in its pathogenesis. Moreover, various chromosome rearrangements were reported in NPC. However, the underlying mechanism of chromosome rearrangement remains unclear. Furthermore, the relationship between EBV and chromosome rearrangement with respect to the pathogenesis of NPC has not been established. We hypothesize that during virus- or stress-induced apoptosis, chromosomes are initially cleaved at the base of the chromatin loop domain structure. Upon DNA repair, cell may survive with rearranged chromosomes.     

Supracubital perineurioma misdiagnosed as carpal tunnel syndrome: case report

Background  

Perineuriomas have been defined as tumorous lesions of the peripheral nerves which derive from perineurial cell proliferation and may be associated with abnormalities on chromosome 22.     

Identification of the <Emphasis Type="Italic">C. elegans</Emphasis>anaphase promoting complex subunit Cdc26 by phenotypic profiling and functional rescue in yeast

Background  

RNA interference coupled with videorecording of C. elegans embryos is a powerful method for identifying genes involved in cell division processes. Here we present a functional analysis of the gene B0511.9, previously identified as a candidate cell polarity gene in an RNAi videorecording screen of chromosome I embryonic lethal genes.     

The association between male infertility and sperm disomy: Evidence for variation in disomy levels among individuals and a correlation between particular semen parameters and disomy of specific chromosome pairs

Background  

The association between infertility and sperm disomy is well documented. Results vary but most report that men with severely compromised semen parameters have a significantly elevated proportion of disomic sperm. The relationship between individual semen parameters and segregation of specific chromosome pairs is however less well reported as is the variation of disomy levels in individual men.     

Dynamic assembly,localization and proteolysis of the <Emphasis Type="Italic">Bacillus subtilis</Emphasis> SMC complex

Background  

SMC proteins are key components of several protein complexes that perform vital tasks in different chromosome dynamics. Bacterial SMC forms a complex with ScpA and ScpB that is essential for chromosome arrangement and segregation. The complex localizes to discrete centres on the nucleoids that during most of the time of the cell cycle localize in a bipolar manner. The complex binds to DNA and condenses DNA in an as yet unknown manner.     

Characterization of DXZ4 conservation in primates implies important functional roles for CTCF binding,array expression and tandem repeat organization on the X chromosome

Background  

Comparative sequence analysis is a powerful means with which to identify functionally relevant non-coding DNA elements through conserved nucleotide sequence. The macrosatellite DXZ4 is a polymorphic, uninterrupted, tandem array of 3-kb repeat units located exclusively on the human X chromosome. While not obviously protein coding, its chromatin organization suggests differing roles for the array on the active and inactive X chromosomes.