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Monkhorst K, de Hoon B, Jonkers I, Mulugeta Achame E, Monkhorst W, Hoogerbrugge J, Rentmeester E, Westerhoff HV, Grosveld F, Grootegoed JA, Gribnau J. The probability to initiate X chromosome inactivation is determined by the X to autosomal ratio and X chromosome specific allelic properties. PLoS One 2009; 4:e5616. [PMID: 19440388 PMCID: PMC2680018 DOI: 10.1371/journal.pone.0005616] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2008] [Accepted: 04/15/2009] [Indexed: 11/26/2022] Open
Abstract
Background In female mammalian cells, random X chromosome inactivation (XCI) equalizes the dosage of X-encoded gene products to that in male cells. XCI is a stochastic process, in which each X chromosome has a probability to be inactivated. To obtain more insight in the factors setting up this probability, we studied the role of the X to autosome (X∶A) ratio in initiation of XCI, and have used the experimental data in a computer simulation model to study the cellular population dynamics of XCI. Methodology/Principal Findings To obtain more insight in the role of the X∶A ratio in initiation of XCI, we generated triploid mouse ES cells by fusion of haploid round spermatids with diploid female and male ES cells. These fusion experiments resulted in only XXY triploid ES cells. XYY and XXX ES lines were absent, suggesting cell death related either to insufficient X-chromosomal gene dosage (XYY) or to inheritance of an epigenetically modified X chromosome (XXX). Analysis of active (Xa) and inactive (Xi) X chromosomes in the obtained triploid XXY lines indicated that the initiation frequency of XCI is low, resulting in a mixed population of XaXiY and XaXaY cells, in which the XaXiY cells have a small proliferative advantage. This result, and findings on XCI in diploid and tetraploid ES cell lines with different X∶A ratios, provides evidence that the X∶A ratio determines the probability for a given X chromosome to be inactivated. Furthermore, we found that the kinetics of the XCI process can be simulated using a probability for an X chromosome to be inactivated that is proportional to the X∶A ratio. These simulation studies re-emphasize our hypothesis that the probability is a function of the concentration of an X-encoded activator of XCI, and of X chromosome specific allelic properties determining the threshold for this activator. Conclusions The present findings reveal that the probability for an X chromosome to be inactivated is proportional to the X∶A ratio. This finding supports the presence of an X-encoded activator of the XCI process.
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Affiliation(s)
- Kim Monkhorst
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Cell Biology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Bas de Hoon
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Iris Jonkers
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- Department of Cell Biology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Eskeatnaf Mulugeta Achame
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | | | - Jos Hoogerbrugge
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Eveline Rentmeester
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Hans V. Westerhoff
- Department of Molecular Cell Physiology, Free University Amsterdam, Amsterdam, the Netherlands
- Manchester Centre for Integrative Systems Biology, Manchester, United Kingdom
| | - Frank Grosveld
- Department of Cell Biology, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - J. Anton Grootegoed
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
| | - Joost Gribnau
- Department of Reproduction and Development, Erasmus MC, University Medical Center, Rotterdam, the Netherlands
- * E-mail:
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Burke BA, Wick MR, King R, Thompson T, Hansen J, Darrae BT, Francke U, Seltzer WK, McCabe ER, Scheithauer BW. Congenital adrenal hypoplasia and selective absence of pituitary luteinizing hormone: a new autosomal recessive syndrome. AMERICAN JOURNAL OF MEDICAL GENETICS 1988; 31:75-97. [PMID: 2906226 DOI: 10.1002/ajmg.1320310111] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Congenital hypoplasia of the adrenal glands (CHA) is a rare condition, particularly in the absence of a central nervous system (CNS) anomaly. Two major types of CHA have been described in the setting of an apparently normal CNS and pituitary: a cytomegalic type usually with X-linked recessive inheritance and a miniature adult type that, when hereditary, is an autosomal recessive trait. Glycerol kinase deficiency (GKD) is an X-linked recessive trait, and it may be associated with CHA and adrenal insufficiency, presumably because of deletion of adjacent X-linked loci. We report on three sibling infants, one male and two females, with normal CNS and lethal CHA of the miniature adult type, selective absence of pituitary LH; two of the infants also had glycerol kinase (GK) activity that was decreased but not in the GKD range. Restriction fragment length polymorphism (RFLP) analysis of X chromosome markers located at Xp21-p22 was carried out on the maternal grandfather, both parents, two of three affected infants, and a living normal brother. The results excluded the X-linked type of this disorder associated with GKD in this family. Autosomal recessive inheritance is most likely.
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Affiliation(s)
- B A Burke
- Department of Laboratory Medicine, University of Minnesota, Minneapolis 55455
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Pettenati MJ, Mirkin LD, Goldstein DJ. Diploid-triploid mosaicism: report of necropsy findings. AMERICAN JOURNAL OF MEDICAL GENETICS 1986; 24:23-8. [PMID: 3706409 DOI: 10.1002/ajmg.1320240104] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
This is the first report of necropsy findings associated with diploid-triploid mosaicism. The important pathological findings are presented and compared to those of pure triploidy and those noted in noninvasive studies of diploid-triploid mosaics. The clinical findings in this patient are compared with those of other reported cases.
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Abstract
Analysis of the morphologic features of 43 complete and 11 mosaic triploid infants delivered at or after 22 weeks of gestation revealed, in addition to well-delineated gross features, a number of new or previously little emphasized histopathologic features. These included testicular Leydig cell hyperplasia, increased levels of hematopoiesis, and ovarian, adrenal, and pulmonary hypoplasia. Some of these findings appeared to be linked to partial hydatidiform mole replacing the normal placenta, which was present in about 70 per cent of the triploid cases. It is important to recognize the breadth of the triploidy spectrum, which ranges from near normalcy to multisystem involvement, and to pay special attention to the placenta. The importance of correct morphologic diagnosis of triploidy is stressed in view of the fact that its occurrence apparently does not prejudice the future reproductive performance of the parents.
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Leschot N, Treffers P, Becker-Bloemkolk M, de Leeuw R, Otten J. Human triploidy: case history and relevance in obstetrics. Eur J Obstet Gynecol Reprod Biol 1978. [DOI: 10.1016/0028-2243(78)90081-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Bocian M, Karp LE, Mohandas T, Sarti D, Lachman R, Wisot A. Intrauterine diagnosis of triploidy: the use of radiologic and ultrasonographic techniques in conjunction with amniocentesis. AMERICAN JOURNAL OF MEDICAL GENETICS 1978; 1:323-32. [PMID: 677172 DOI: 10.1002/ajmg.1320010309] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Saadi AA, Juliar JF, Harm J, Brough AJ, Perrin EV, Chen H. Triploidy syndrome. A report on two live-born (69, XXY) and one still-born (69, XXX) infants. Clin Genet 1976; 9:43-50. [PMID: 174849 DOI: 10.1111/j.1399-0004.1976.tb01548.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Two live-born cases, 69,XXY and one stillbirth, 69,XXX are reported. Further evidence is presented to delineate the triploidy syndrome. Common external and internal features which characterize the triploidy syndrome are low-set ears, hypertelorism, colobomata, syndactyly, simian creases, microphallus, undescended testes, scrotal aplasia, anomalous heart and hypoplasia of kidneys and adrenals. The triploidy syndrome encompasses features found in trisomies 13, 18 and 21. We suggest that the abnormal development of the triploidy infants is the result of the mentioned trisomies and their subsequent effect on the remaining genome.
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Schinzel A, Hayashi K, Schmid W, Knecht B, Tuschy G, Boltshauser E. [Triploidy as a cause of midtrimester gestosis(author's transl)]. ARCHIV FUR GYNAKOLOGIE 1975; 218:113-23. [PMID: 1174023 DOI: 10.1007/bf01395911] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The authors report a case of triploidy in a prematurely born child. The pregnancy was complicated by severe toxemia beginning during the second trimester and terminating in preeclampsia leading to cesarian section in the 33th week of gestation. The externally female child was underweight, hypotonic and asphyctic and died shortly after birth. She exhibited a complex brain malformation including excessive hydrocephaly, cebocephaly and aplasia of the piturary gland, and multiple dysmorphic signs. Autopsy revealed hypoplasia and dysplasia of the adrenal glands; no uterus, tubes and ovaries were present, but no testes were found. The placenta showed localized hydatidiform degeneration and was relatively large. The karyotype was 69,XXY, and with the aid of fluorescence markers, paternal origin of the additional haploid chromosome set was demonstrated. Typical findings in pregnancies with fetal triploidy are discussed and the possibility of prenatal diagnosis of triploidy by chromosome analysis in cultivated amniotic fluid cells is pointed out.
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