scholarly journals Skewness of X-chromosome inactivation increases with age and varies across birth cohorts in elderly Danish women

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jonas Mengel-From ◽  
Rune Lindahl-Jacobsen ◽  
Marianne Nygaard ◽  
Mette Soerensen ◽  
Karen Helene Ørstavik ◽  
...  
Keyword(s):  
X Chromosome ◽  
X Chromosome Inactivation ◽  
X Inactivation ◽  
Chromosome Inactivation ◽  
Chromosomal Mosaicism ◽  
Birth Cohorts ◽  
Cross Sectional ◽  
Time Points ◽  
Age Related ◽  
Skewed X Chromosome Inactivation

AbstractMosaicism in blood varies with age, and cross-sectional studies indicate that for women, skewness of X-chromosomal mosaicism increases with age. This pattern could, however, also be due to less X-inactivation in more recent birth cohorts. Skewed X-chromosome inactivation was here measured longitudinally by the HUMARA assay in 67 septuagenarian and octogenarian women assessed at 2 time points, 10 years apart, and in 10 centenarian women assessed at 2 time points, 2–7 years apart. Skewed X-chromosome inactivation was also compared in 293 age-matched septuagenarian twins born in 1917–1923 and 1931–1937, and 212 centenarians born in 1895, 1905 and 1915. The longitudinal study of septuagenarians and octogenarians revealed that 16% (95% CI 7–29%) of the women developed skewed X-inactivation over a 10-year period. In the cross-sectional across-birth cohort study, the earlier-born septuagenarian (1917–1923) and centenarian women (1895) had a higher degree of skewness than the respective recent age-matched birth cohorts, which indicates that the women in the more recent cohorts, after the age of 70, had not only changed degree of skewness with age, they had also undergone less age-related hematopoietic sub-clone expansion. This may be a result of improved living conditions and better medical treatment in the more recent birth cohorts.

X-linked CNV and skewed X-chromosome inactivation

2020 ◽  
pp. 19-21
Author(s):  
Е.А. Фонова ◽  
Е.Н. Толмачева ◽  
А.А. Кашеварова ◽  
М.Е. Лопаткина ◽  
К.А. Павлова ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Intellectual Disability ◽  
X Chromosome ◽  
Copy Number ◽  
Copy Number Variations ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Chromosome X ◽  
Skewed X Chromosome Inactivation

Смещение инактивации Х-хромосомы может быть следствием и маркером нарушения клеточной пролиферации при вариациях числа копий ДНК на Х-хромосоме. Х-сцепленные CNV выявляются как у женщин с невынашиванием беременности и смещением инактивации Х-хромосомы (с частотой 33,3%), так и у пациентов с умственной отсталостью и смещением инактивацией у их матерей (с частотой 40%). A skewed X-chromosome inactivation can be a consequence and a marker of impaired cell proliferation in the presence of copy number variations (CNV) on the X chromosome. X-linked CNVs are detected in women with miscarriages and a skewed X-chromosome inactivation (with a frequency of 33.3%), as well as in patients with intellectual disability and skewed X-chromosome inactivation in their mothers (with a frequency of 40%).

scholarly journals Skewed X-Chromosome Inactivation Is a Common Feature of X-Linked Mental Retardation Disorders

2002 ◽  
Vol 71 (1) ◽  
pp. 168-173 ◽  
Author(s):  
Robert M. Plenge ◽  
Roger A. Stevenson ◽  
Herbert A. Lubs ◽  
Charles E. Schwartz ◽  
Huntington F. Willard
Keyword(s):  
Mental Retardation ◽  
X Chromosome ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Skewed X Chromosome Inactivation

scholarly journals Extremely skewed X-chromosome inactivation is increased in pre-eclampsia

2006 ◽  
Vol 121 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Elif Uz ◽  
Ismail Dolen ◽  
Atakan R. Al ◽  
Tayfun Ozcelik
Keyword(s):  
X Chromosome ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Skewed X Chromosome Inactivation

Skewed X-chromosome inactivation plays a crucial role in the onset of symptoms in carriers of Becker muscular dystrophy

2017 ◽  
Vol 19 (4) ◽  
pp. e2952 ◽  
Author(s):  
Emanuela Viggiano ◽  
Esther Picillo ◽  
Manuela Ergoli ◽  
Alessandra Cirillo ◽  
Stefania Del Gaudio ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
X Chromosome ◽  
Crucial Role ◽  
Becker Muscular Dystrophy ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Skewed X Chromosome Inactivation

X-chromosome inactivation in XX androgenetic mouse embryos surviving implantation

Development ◽  
2000 ◽  
Vol 127 (19) ◽  
pp. 4137-4145 ◽  
Author(s):  
I. Okamoto ◽  
S. Tan ◽  
N. Takagi
Keyword(s):  
X Chromosome ◽  
Ectopic Expression ◽  
Blastocyst Stage ◽  
X Chromosome Inactivation ◽  
X Inactivation ◽  
Chromosome Inactivation ◽  
Current View ◽  
Replication Banding ◽  
Xist Rna ◽  
Morula Stage

Using genetic and cytogenetic markers, we assessed early development and X-chromosome inactivation (X-inactivation) in XX mouse androgenones produced by pronuclear transfer. Contrary to the current view, XX androgenones are capable of surviving to embryonic day 7.5, achieving basically random X-inactivation in all tissues including those derived from the trophectoderm and primitive endoderm that are characterized by paternal X-activation in fertilized embryos. This finding supports the hypothesis that in fertilized female embryos, the maternal X chromosome remains active until the blastocyst stage because of a rigid imprint that prevents inactivation, whereas the paternal X chromosome is preferentially inactivated in extra-embryonic tissues owing to lack of such imprint. In spite of random X-inactivation in XX androgenones, FISH analyses revealed expression of stable Xist RNA from every X chromosome in XX and XY androgenonetic embryos from the four-cell to morula stage. Although the occurrence of inappropriate X-inactivation was further suggested by the finding that Xist continues ectopic expression in a proportion of cells from XX and XY androgenones at the blastocyst and the early egg cylinder stage, a replication banding study failed to provide positive evidence for inappropriate X-inactivation at E6. 5.

Investigation of variability among mouse aggregation chimaeras and X-chromosome inactivation mosaics

Development ◽  
1984 ◽  
Vol 84 (1) ◽  
pp. 309-329
Author(s):  
John D. West ◽  
Theodor Bücher ◽  
Ingrid M. Linke ◽  
Manfred Dünnwald
Keyword(s):  
X Chromosome ◽  
Phosphoglycerate Kinase ◽  
X Chromosome Inactivation ◽  
Yolk Sac ◽  
X Inactivation ◽  
Chromosome Inactivation ◽  
Cell Populations ◽  
Primitive Endoderm ◽  
Female Progeny ◽  
Positive Correlations

Mouse aggregation chimaeras were produced by aggregating C3H/HeH and C3H/HeHa—Pgk-1a/Ws embryos. At mid-term the proportions of the two cell populations in these conceptuses and the X-inactivation mosaic female progeny of C3H/HeH ♀ × C3H/HeHa—Pgk-1a/Ws ♂ matings were estimated using quantitative electrophoresis of phosphoglycerate kinase (PGK-1) allozymes. The percentage of PGK-1B was more variable in the foetus, amnion and yolk sac mesoderm of the chimaeras than in the corresponding tissues of the mosaic conceptuses. Positive correlations were found for the percentage of PGK-1B between these three primitive ectoderm tissues in both chimaeras and mosaics and between the two primitive endoderm tissues (yolk sac endoderm and parietal endoderm) of the chimaeras. There was no significant correlation between the primitive ectoderm and primitive endoderm tissues of the chimaeras. The results suggest that unequal allocation of cell populations to the primitive ectoderm and primitive endoderm considerably increases the variability among chimaeras but variation probably exists before this segregation occurs. The variation that arises before and at this allocation event is present before X-chromosome inactivation occurs in the primitive ectoderm lineage and explains why the proportions of the two cell populations are more variable among chimaeras than mosaics. Additional variation arises within the primitive ectoderm lineage, after X-inactivation. This variation may be greater in chimaeras than mosaics but the evidence is inconclusive. The results also have some bearing on the nature of the allocation of cells to the primitive ectoderm and primitive endoderm lineages and the timing of X-chromosome inactivation in the primitive ectoderm lineage.

Regulation of imprinted X-chromosome inactivation in mice by Tsix

Development ◽  
2001 ◽  
Vol 128 (8) ◽  
pp. 1275-1286 ◽  
Author(s):  
T. Sado ◽  
Z. Wang ◽  
H. Sasaki ◽  
E. Li
Keyword(s):  
X Chromosome ◽  
X Chromosome Inactivation ◽  
X Inactivation ◽  
Chromosome Inactivation ◽  
Maternal Allele ◽  
Xist Expression ◽  
Developmental Defects ◽  
X Chromosomes ◽  
Embryonic Tissues ◽  
Early Embryonic Lethality

In mammals, X-chromosome inactivation is imprinted in the extra-embryonic lineages with paternal X chromosome being preferentially inactivated. In this study, we investigate the role of Tsix, the antisense transcript from the Xist locus, in regulation of Xist expression and X-inactivation. We show that Tsix is transcribed from two putative promoters and its transcripts are processed. Expression of Tsix is first detected in blastocysts and is imprinted with only the maternal allele transcribed. The imprinted expression of Tsix persists in the extra-embryonic tissues after implantation, but is erased in embryonic tissues. To investigate the function of Tsix in X-inactivation, we disrupted Tsix by insertion of an IRES(β)geo cassette in the second exon, which blocked transcripts from both promoters. While disruption of the paternal Tsix allele has no adverse effects on embryonic development, inheritance of a disrupted maternal allele results in ectopic Xist expression and early embryonic lethality, owing to inactivation of both X chromosomes in females and single X chromosome in males. Further, early developmental defects of female embryos with maternal transmission of Tsix mutation can be rescued by paternal inheritance of the Xist deletion. These results provide genetic evidence that Tsix plays a crucial role in maintaining Xist silencing in cis and in regulation of imprinted X-inactivation in the extra-embryonic tissues.

scholarly journals Persistence of skewed X-chromosome inactivation in pre-B acute lymphoblastic leukemia of a female ATRX mutation carrier

2019 ◽  
Vol 3 (17) ◽  
pp. 2627-2631
Author(s):  
Christian P. Bradley ◽  
Cai Chen ◽  
Karolyn A. Oetjen ◽  
Cheng Yan ◽  
Reema Panjwani ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
X Chromosome ◽  
Germline Mutation ◽  
Mutation Carrier ◽  
Lymphoblastic Leukemia ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
Female Carrier ◽  
Key Points ◽  
Skewed X Chromosome Inactivation

Key Points Leukemic blasts of a female carrier of an ATRX germline mutation have persistently skewed inactivation of the X chromosome. Germline mutation in leukemia needs to be interpreted with caution because it is not always pathologic.

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