X inactivation in triploidy and trisomy: the search for autosomal transfactors that choose the active X
| Autor: | Patricia A. Jacobs, Gail Stetten, Barbara R. Migeon, Kara Pappas, Carolyn Trunca |
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| Rok vydání: | 2007 |
| Předmět: |
Male
RNA Untranslated Aneuploidy Trisomy Biology X-inactivation Polyploidy Mice X Chromosome Inactivation Dosage Compensation Genetic Genetics medicine Animals Humans Skewed X-inactivation Genetics (clinical) X chromosome Chromosomes Human X Autosome Dosage compensation medicine.disease Molecular biology Gene Expression Regulation Trans-Activators Female RNA Long Noncoding XIST Ploidy |
| Zdroj: | European Journal of Human Genetics. 16:153-162 |
| ISSN: | 1476-5438 1018-4813 |
| Popis: | Only one X chromosome functions in diploid human cells irrespective of the sex of the individual and the number of X chromosomes. Yet, as we show, more than one X is active in the majority of human triploid cells. Therefore, we suggest that (i) the active X is chosen by repression of its XIST locus, (ii) the repressor is encoded by an autosome and is dosage sensitive, and (iii) the extra dose of this key repressor enables the expression of more than one X in triploid cells. Because autosomal trisomies might help locate the putative dosage sensitive trans-acting factor, we looked for two active X chromosomes in such cells. Previously, we reported that females trisomic for 18 different human autosomes had only one active X and a normal inactive X chromosome. Now we report the effect of triplication of the four autosomes not studied previously; data about these rare trisomies - full or partial - were used to identify autosomal regions relevant to the choice of active X. We find that triplication of the entire chromosomes 5 and 11 and parts of chromosomes 1 and 19 is associated with normal patterns of X inactivation, excluding these as candidate regions. However, females with inherited triplications of 1p21.3-q25.3, 1p31 and 19p13.2-q13.33 were not ascertained. Thus, if a single key dose-sensitive gene induces XIST repression, it could reside in one of these locations. Alternatively, more than one dosage-sensitive autosomal locus is required to form the repressor complex. |
| Databáze: | OpenAIRE |
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