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Dosage compensation

About: Dosage compensation is a research topic. Over the lifetime, 1920 publications have been published within this topic receiving 124589 citations.


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Journal ArticleDOI
01 Jul 2019-Genetics
TL;DR: Results indicate that DCC-mediated transcription repression is associated with a reduction in the activity of X chromosomal gene regulatory elements.
Abstract: Condensins are evolutionarily conserved protein complexes that are required for chromosome segregation during cell division and genome organization during interphase. In Caenorhabditis elegans, a specialized condensin, which forms the core of the dosage compensation complex (DCC), binds to and represses X chromosome transcription. Here, we analyzed DCC localization and the effect of DCC depletion on histone modifications, transcription factor binding, and gene expression using chromatin immunoprecipitation sequencing and mRNA sequencing. Across the X, the DCC accumulates at accessible gene regulatory sites in active chromatin and not heterochromatin. The DCC is required for reducing the levels of activating histone modifications, including H3K4me3 and H3K27ac, but not repressive modification H3K9me3. In X-to-autosome fusion chromosomes, DCC spreading into the autosomal sequences locally reduces gene expression, thus establishing a direct link between DCC binding and repression. Together, our results indicate that DCC-mediated transcription repression is associated with a reduction in the activity of X chromosomal gene regulatory elements.

13 citations

Journal ArticleDOI
TL;DR: The functional locus for α-amylase (Amy) inDrosophila miranda is in the evolutionarily new X2 chromosome, and on the diet with glucose,Amy expression was repressed in both WT 10 and S 204 larvae and male larvae of S 204 displayed dosage compensation for amylase activity.
Abstract: The functional locus for α-amylase (Amy) inDrosophila miranda is in the evolutionarily new X2 chromosome. X2 evolved from an autosome in response to an ancestral autosome-Y translocation that gave rise to the “neo-Y” chromosome of this species. Y-linkedAmy, if still present in the ancestrally translocated element, is unexpressed. Dosage compensation for amylase activity was examined in larvae of the S 204 strain. Since dietary glucose is known to repressAmy expression inDrosophila melanogaster, dosage compensation of amylase activity in male larvae ofD. miranda was tested by rearing larvae of both sexes on yeast diets with or without a glucose supplement. The WT 10 strain ofDrosophila persimilis, a sibling species in whichAmy is autosomally linked, was used as a reference for tests of amylase activity differences between the sexes. On the diet with glucose,Amy expression was repressed in both WT 10 and S 204 larvae and male larvae of S 204 displayed dosage compensation for amylase activity. On the nonrepressing diet consisting of yeast alone, S 204 continued to display dosage compensation.

13 citations

Journal ArticleDOI
TL;DR: It is concluded that the direction and extent of chromosome segregation from these hybrids depends on the dosage of some factor contained in the parent cells; because the volumes of polyploid cells are proportional to chromosome number, this factor could be chromosomal, nuclear, or cytoplasmic.
Abstract: To determine whether the dosage of some parental factor influences the direction and extent of chromosome segregation, I have constructed hybrids between polyploid series of mouse and Chinese hamster lines. The input ratio of mouse:hamster chromosomes varied from 3.3 (in hybrids between diploid hamster and polyploid mouse cells) and 0.9 (in hybrids between polyploid hamster and near-diploid mouse cells). Mouse chromosomes were retained and hamster chromosomes were lost from all hybrids with input ratios greater than or equal to 1.3; the extent of hamster chromosome loss increased from 25 to 60% as the proportion of mouse chromosomes was increased. Reverse segregation was observed in hybrids in which the ratio was 0.9; hybrids between polyploid hamster and diploid mouse cells retained most hamster chromosomes and lost 52% of mouse chromosomes. I conclude that the direction and extent of chromosome segregation from these hybrids depends on the dosage of some factor contained in the parent cells; because the volumes of polyploid cells are proportional to chromosome number, this factor could be chromosomal, nuclear, or cytoplasmic. Dosage differences should therefore be considered when comparing chromosome segregation from hybrids with cells of the same species combination, but which might differ in chromosome number (e.g., diploid lines and established lines), or cell volume (e.g., cells from different tissues).

13 citations

Journal ArticleDOI
TL;DR: It is shown that SPT5 interacts directly with MSL1 in vitro and is required downstream of MSL complex recruitment, providing the first mechanistic data corroborating the elongation model of dosage compensation.
Abstract: In Drosophila, the MSL (Male Specific Lethal) complex up regulates transcription of active genes on the single male X-chromosome to equalize gene expression between sexes One model argues that the MSL complex acts upon the elongation step of transcription rather than initiation In an unbiased forward genetic screen for new factors required for dosage compensation, we found that mutations in the universally conserved transcription elongation factor Spt5 lower MSL complex dependent expression from the miniwhite reporter gene in vivo We show that SPT5 interacts directly with MSL1 in vitro and is required downstream of MSL complex recruitment, providing the first mechanistic data corroborating the elongation model of dosage compensation

13 citations

Journal ArticleDOI
TL;DR: The karyotype of the pine woods treefrog, Hyla femoralis, is characterized by primitive XY♀/XX♂ sex chromosomes, and the consequences of the loss of about 50% of ribosomal RNA genes for the viability of male individuals and spermatogenesis are discussed.
Abstract: The karyotype of the pine woods treefrog, Hyla femoralis, is characterized by primitive XY female/XX male sex chromosomes. The sole difference between the X and the Y is the presence of a nucleolus organizer region (NOR) in the X. Due to a deletion of the NOR in the Y, this chromosome is distinctly smaller than the X. Since no autosomal NORs exist in the karyotype of this species, the NOR deletion in the Y results in a sex-specific difference in the number of ribosomal RNA genes, with a female:male ratio of about 2:1. Interphase nuclei of male animals contain always one silver-stained nucleolus, whereas most nuclei of female specimens exhibit two nucleoli. This is in agreement with the absence of dosage compensation for sex-linked genes in amphibian cells. The consequences of the loss of about 50% of ribosomal RNA genes for the viability of male individuals and spermatogenesis are discussed.

13 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202330
202272
202183
202051
201980
201870