scispace - formally typeset
Search or ask a question
Topic

X chromosome

About: X chromosome is a research topic. Over the lifetime, 9862 publications have been published within this topic receiving 407354 citations. The topic is also known as: GO:0000805 & chrX.


Papers
More filters
Journal ArticleDOI
TL;DR: A unique and complex karyotypic rearrangement involving chromosomes X, 3, 7, and 21 is reported, providing biochemical evidence for nonrandom expression of X-linked genes in balanced X-autosome translocations and further evidence for the stability of the inactive X phenotype in hybrid cells.
Abstract: We report a unique and complex karyotypic rearrangement involving chromosomes X, 3, 7, and 21. Blood cells and fibroblasts from the proband do not express the maternal allele for glucose-6-phosphate dehydrogenase (G6PD), providing biochemical evidence for nonrandom expression of X-linked genes in balanced X-autosome translocations. The break point on the X chromosome, at the junction of Xq27-Xq28, separates the loci for hypoxanthine phosphoribosyltransferase (HPRT) and G6PD. Studies of mouse-human hybrids derived from the proband's cells indicate that G6PD, at q28, is clearly distal to all other X loci now assigned. From these and previous studies, we can localize HPRT to that segment between Xq26 and Xq27. The studies also provide further evidence for the stability of the inactive X phenotype in hybrid cells.

133 citations

Journal ArticleDOI
TL;DR: Data suggest that risk of SLE is related to a gene dose effect for the X chromosome, and that a gene that avoids X inactivation will have a higher level of expression in persons with two X chromosomes.

133 citations

Journal ArticleDOI
06 Jan 1989-Science
TL;DR: Polymerase chain reaction analysis suggests both Y loci are transcribed in adult testes, and mYfin sequences have been duplicated several times in the mouse, although they are not duplicated in humans.
Abstract: Isolation and mapping of a mouse complementary DNA sequence (mouse Y-finger) encoding a multiple, potential zinc-binding, finger protein homologous to the candidate human testis-determining factor gene is reported. Four similar sequences were identified in Hind III-digested mouse genomic DNA. Two (7.2 and 2.0 kb) were mapped to the Y chromosome. Only the 2.0-kb fragment, however, was correlated with testis determination. Polymerase chain reaction analysis suggests both Y loci are transcribed in adult testes. A 3.6-kb fragment was mapped to the X chromosome between the T16H and T6R1 translocation breakpoints, and a fourth (6.0 kb) was mapped to chromosome 10. Hence, mYfin sequences have been duplicated several times in the mouse, although they are not duplicated in humans.

133 citations

Journal ArticleDOI
TL;DR: Almost all active genes on the X chromosome are associated with robust H4 Lys16 acetylation (H4K16ac), the histone modification catalyzed by the MSL complex, suggesting a common principle for the establishment of active and silenced chromatin domains.
Abstract: Drosophila MSL complex binds the single male X chromosome to upregulate gene expression to equal that from the two female X chromosomes. However, it has been puzzling that ~25% of transcribed genes on the X do not stably recruit MSL complex. Here, we find that almost all active genes on the X are associated with robust H4 Lys16 acetylation (H4K16ac), the histone modification catalyzed by MSL complex. The distribution of H4K16ac is much broader than that of MSL complex, and our results favor the idea that chromosome-wide H4K16ac reflects transient association of MSL complex, occurring through spreading or chromosomal looping. Our results parallel those of localized Polycomb repressive complex and its more broadly distributed H3K27me3 chromatin mark, suggesting a common principle for the establishment of active and silenced chromatin domains.

133 citations

Journal ArticleDOI
01 Mar 1989-Genetics
TL;DR: The results accord with genetic studies of other taxa, and support the view that both Haldane's rule (heterogametic F1 sterility or inviability) and the large effect of the X chromosome on reproductive isolation result from the accumulation by natural selection of partially recessive or underdominant mutations.
Abstract: In a genetic study of postzygotic reproductive isolation among species of the Drosophila virilis group, we find that the X chromosome has the largest effect on male and female hybrid sterility and inviability. The X alone has a discernible effect on postzygotic isolation between closely related species. Hybridizations involving more distantly related species also show large X-effects, although the autosomes may also play a role. In the only hybridization yet subjected to such analysis, we show that hybrid male and female sterility result from the action of different X-linked loci. Our results accord with genetic studies of other taxa, and support the view that both Haldane's rule (heterogametic F1 sterility or inviability) and the large effect of the X chromosome on reproductive isolation result from the accumulation by natural selection of partially recessive or underdominant mutations. We also describe a method that allows genetic analysis of reproductive isolation between species that produce completely sterile or inviable hybrids. Such species pairs, which represent the final stage of speciation, cannot be analyzed by traditional methods. The X chromosome also plays an important role in postzygotic isolation between these species.

132 citations


Network Information
Related Topics (5)
Exon
38.3K papers, 1.7M citations
90% related
Mutation
45.2K papers, 2.6M citations
89% related
Gene mutation
41.4K papers, 1.3M citations
87% related
Intron
23.8K papers, 1.3M citations
86% related
Locus (genetics)
42.7K papers, 2M citations
85% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202372
2022124
2021192
2020179
2019190
2018186