scholarly journals Mouse endogenous X-linked genes do not show lineage-specific delayed inactivation during development

1995 ◽  
Vol 65 (3) ◽  
pp. 223-227 ◽  
Author(s):  
Jeanne M. Lebon ◽  
Patrick P. L. Tam ◽  
Judith Singer-Sam ◽  
Arthur D. Riggs ◽  
Seong-Seng Tan

SummaryX chromosome inactivation (XCI) has been assumed to be complete in all cells of female mouse embryos at about 6 d post coitum (dpc). However, a recent study on β-galactosidase expression of an X-linkedlacZtransgene suggests that XCI is probably not complete several days after this time in some lineages. To help resolve this issue, we analysed XCI in embryos which carry the T(X;16)16H (Searle's) translocation and are heterozygous at the X-linkedHprtandPgk-1genes. The quantitative RT-PCR single nucleotide primer extension (SNuPE) assay was used to measureHprtandPgk-1allele-specific transcripts in embryos 9·5 dpc. No transcripts from the normal X chromosome were found in any of the tissues tested, indicating that inactivation was complete for these endogenous genes.

Nature ◽  
1978 ◽  
Vol 274 (5670) ◽  
pp. 500-503 ◽  
Author(s):  
CHARLES J. EPSTEIN ◽  
SANDRA SMITH ◽  
BRUCE TRAVIS ◽  
GEORGIANNE TUCKER

Development ◽  
1982 ◽  
Vol 71 (1) ◽  
pp. 11-24
Author(s):  
Sohaila Rastan

The onset of X-chromosome inactivation was investigated cytologically in postimplantation female mouse embryos of age 5½, 6½ and 7½ days post-coitum (d.p.c.) and in the isolated epiblasts of 6 d.p.c. embryos before primitive streak formation using a heat/hypotonic technique to reveal the inactive X chromosome by differentially dark staining with Giemsa. The results indicate that X inactivation has taken place in all the cells of the so-called ‘undifferentiated’ epiblast by 6 d.p.c. before primitive streak formation. Further evidence is presented to suggest that X inactivation is complete in all cells of the mouse embryo by 5½ d.p.c.


2017 ◽  
Vol 16 ◽  
pp. 117693511774727 ◽  
Author(s):  
Jian Wang ◽  
Rajesh Talluri ◽  
Sanjay Shete

To address the complexity of the X-chromosome inactivation (XCI) process, we previously developed a unified approach for the association test for X-chromosomal single-nucleotide polymorphisms (SNPs) and the disease of interest, accounting for different biological possibilities of XCI: random, skewed, and escaping XCI. In the original study, we focused on the SNP-disease association test but did not provide knowledge regarding the underlying XCI models. One can use the highest likelihood ratio (LLR) to select XCI models (max-LLR approach). However, that approach does not formally compare the LLRs corresponding to different XCI models to assess whether the models are distinguishable. Therefore, we propose an LLR comparison procedure (comp-LLR approach), inspired by the Cox test, to formally compare the LLRs of different XCI models to select the most likely XCI model that describes the underlying XCI process. We conduct simulation studies to investigate the max-LLR and comp-LLR approaches. The simulation results show that compared with the max-LLR, the comp-LLR approach has higher probability of identifying the correct underlying XCI model for the scenarios when the underlying XCI process is random XCI, escaping XCI, or skewed XCI to the deleterious allele. We applied both approaches to a head and neck cancer genetic study to investigate the underlying XCI processes for the X-chromosomal genetic variants.


2010 ◽  
Vol 1 (4) ◽  
pp. 657-661 ◽  
Author(s):  
YOSHIHISA YANO ◽  
TOMOHIRO YANO ◽  
ANNA KINOSHITA ◽  
AI MATOBA ◽  
TADAYOSHI HASUMA ◽  
...  

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