scholarly journals Parental influences on X chromosome expression

1985 ◽  
Vol 45 (1) ◽  
pp. 95-100 ◽  
Author(s):  
Lesley M. Forrester ◽  
J. D. Ansell
Keyword(s):  
X Chromosome ◽  
Phosphoglycerate Kinase ◽  
Parental Influences ◽  
Allelic Combination ◽  
The Relationship ◽  
Maternal Imprinting

SummaryUsing mice that were mosaics for both Xce and phosphoglycerate kinase (Pgk-1) alleles, we have established that the parental source of the Xce gene may affect the probability with which the X chromosome carrying it will remain active. This effect was seen in one allelic combination of Xce but not in another. The relationship between these effects and other phenomena of maternal ‘imprinting’ is discussed.

Random X-chromosome inactivation in female primordial germ cells in the mouse

Development ◽  
1981 ◽  
Vol 64 (1) ◽  
pp. 251-258
Author(s):  
Andy McMahon ◽  
Mandy Fosten ◽  
Marilyn Monk
Keyword(s):  
X Chromosome ◽  
Germ Cells ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Phosphoglycerate Kinase ◽  
X Chromosome Inactivation ◽  
Yolk Sac ◽  
Chromosome Inactivation ◽  
X Chromosomes

The pattern of expression of the two X chromosomes was investigated in pre-meiotic germ cells from 12½-day-old female embryos heterozygous for the variant electrophoretic forms of the X-linked enzyme phosphoglycerate kinase (PGK-1). If such germ cells carry the preferentially active Searle's translocated X chromosome (Lyon, Searle, Ford & Ohno, 1964), then only the Pgk-1 allele on this chromosome is expressed. This confirms Johnston's evidence (1979,1981) that Pgk-1 expression reflects a single active X chromosome at this time. Extracts of 12½-day germ cells from heterozygous females carrying two normal X chromosomes show both the A and the B forms of PGK; since only one X chromosome in each cell is active, different alleles must be expressed in different cells, suggesting that X-chromosome inactivation is normally random in the germ line. This result makes it unlikely that germ cells are derived from the yolk-sac endoderm where the paternally derived X chromosome is preferentially inactivated. In their pattern of X-chromosome inactivation, germ cells evidently resemble other tissues derived from the epiblast.

scholarly journals Xce genotype has no impact on the effect of imprinting on X-chromosome expression in the mouse yolk sac endoderm

1986 ◽  
Vol 47 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Theodor Bücher ◽  
Ingrid M. Linke ◽  
Manfred Dünnwald ◽  
John D. West ◽  
Bruce M. Cattanach
Keyword(s):  
X Chromosome ◽  
Phosphoglycerate Kinase ◽  
Yolk Sac ◽  
Chromosome Inactivation ◽  
Preferential Expression ◽  
Controlling Element

SummaryThe effect of the Xce (x-chromosome controlling element) genotype on the randomness of X-chromosome inactivation in the mouse was studied by monitoring the expression of the X-linked locus pgk-1. The main aim was to test whether the Xce genotype modified the preferential expression of the maternally derived X-chromosome in the yolk sac endoderm. Quantitative electrophoresis of phosphoglycerate kinase (PGK-1) was used to study Pgk-1 expression in the foetus, yolk sac mesoderm and yolk sac endoderm at 13½ days post coitum. The Xcea/Xcec genotype caused non-random X-chromosome expression in the foetus and yolk sac mesoderm. However, there was no evidence that the Xce genotype moderates the preferential expression of the maternally derived X-chromosome in the yolk sac endoderm, as reported by Rastan & Cattanach (1983).

GONADAL DYSGENESIS WITH XX-ISOCHROMOSOME CONSTITUTION AND ABNORMAL THYROID PATTERNS

1967 ◽  
Vol 54 (4) ◽  
pp. 609-617 ◽  
Author(s):  
R. G. Milet ◽  
E. R. Plunkett ◽  
D. H. Carr
Keyword(s):  
Autoimmune Disease ◽  
X Chromosome ◽  
Gonadal Dysgenesis ◽  
Ridge Count ◽  
Suppurative Otitis Media ◽  
Lyon Hypothesis ◽  
Relationship Of ◽  
The Relationship ◽  
Thyroid Abnormalities

ABSTRACT The authors report a female patient with XXi constitution for the long arm of the X chromosome associated with thyroid abnormalities, high digital ridge count and chronic suppurative otitis media. This is followed by a discussion of the correlation between genotype and phenotype, comment on the Lyon hypothesis, the relationship of thyroid abnormalities to this condition, autoimmune disease, unbalanced sex chromosomal constitution and the association with a high total digital ridge count. Finally a single hypothesis is proposed for the associated clinical entities that have been found and the suggestion that the classification of this particular type of gonadal dysgenesis be considered as a new syndrome, the »XX-isochromosome syndrome«.

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.

Demethylation of specific sites in the 5' region of the inactive X-linked human phosphoglycerate kinase gene correlates with the appearance of nuclease sensitivity and gene expression

1988 ◽  
Vol 8 (11) ◽  
pp. 4692-4699
Author(s):  
R S Hansen ◽  
N A Ellis ◽  
S M Gartler
Keyword(s):  
Cell Lines ◽  
X Chromosome ◽  
Transcriptional Activation ◽  
Hybrid Cell ◽  
Methylation Status ◽  
Phosphoglycerate Kinase ◽  
Kinase Gene ◽  
Inactive X Chromosome ◽  
Phosphoglycerate Kinase Gene ◽  
Hypoxanthine Guanine Phosphoribosyltransferase

X8/6T2, a hamster-human hybrid cell line which contains an inactive human X chromosome, was treated with 5-azacytidine and selected for derepression of hypoxanthine-guanine phosphoribosyltransferase. Clones were examined for coreactivation of the phosphoglycerate kinase gene (Pgk). Of 68 of these hybrids, approximately 20% expressed measurable human phosphoglycerate kinase (PGK) activity. A 600-base-pair region of the Pgk 5' CpG cluster was examined for the methylation status of eight CCGG sites (site 1 being 5'-most) in a number of PGK-negative and PGK-positive cell lines. The inactive X chromosome is normally methylated at all eight sites, and this was also true for the majority of X8/6T2 cells. However, several PGK-negative hybrids were demethylated in the site 3 to site 6 region. PGK activity correlated with demethylation at both sites 6 and 7. The data for PGK-positive and -negative hybrids indicate that demethylation at or near site 7 was necessary for reactivation of Pgk. Chromatin sensitivity to MspI digestion in the nuclei of male lymphoblastoid cells and several PGK-positive and PGK-negative hybrids was examined. PGK-positive cell lines were hypersensitive to digestion, while PGK-negative hybrids were resistant. Cleavage at sites 6 and 7 was observed in all PGK-positive cell lines at each MspI concentration examined. Sites 7 and 8 were less accessible to digestion than site 6. Cleavage in the site 2 to site 5 region was observable at the lowest MspI concentration. In most PGK-positive hybrids, a nonspecific endogenous nuclease detected the presence of a hypersensitive region spanning at least 450 base pairs, bounded at the 3' end near HpaII site 6. Nuclease hypersensitivity appears to be related to promoter activity, because sites 7 and 8 are in transcribed regions of the gene. These data indicate that specific sites within the CpG cluster have a dominant controlling influence over the Pgk promoter conformation and the transcriptional activation of Pgk.

scholarly journals Unbalanced X chromosome mosaicism in B cells of mice with X-linked immunodeficiency.

1983 ◽  
Vol 158 (3) ◽  
pp. 920-931 ◽  
Author(s):  
M H Nahm ◽  
J W Paslay ◽  
J M Davie
Keyword(s):  
B Cells ◽  
B Cell ◽  
B Lymphocytes ◽  
X Chromosome ◽  
Cell Subset ◽  
Phosphoglycerate Kinase ◽  
Mutant Gene ◽  
Abnormal Development ◽  
Female Mice ◽  
Chromosomal Genes

The immunodeficiency in CBA/N mice is reflected by abnormal development of a subset of B lymphocytes. However, it is not clear how xid, the mutant gene in CBA/N mice, affects the development of this subset. Specifically, it is not known if the xid gene influences the development of the B cell subset directly or indirectly by providing the improper developmental milieu through effects on other cells. We investigated this question using female mice heterozygous for two x chromosomal genes, xid and Pgk-1 (phosphoglycerate kinase-1). Since females are mosaic because of x chromosome inactivation, their lymphocytes can be studied for the choice of the x chromosome, using the two PGK-1 isoenzymes as the cytological marker. We find that B lymphocytes in the spleen prefer the x chromosome without xid while the remaining splenocytes and cells from other tissues do not. This suggests that xid affects B lymphocytes directly and not through their developmental milieu. Furthermore, our data suggest that the precursors for IgG1- and IgG3-producing cells may be both few and different.

scholarly journals Further evidence for the importance of parental source of the Xce allele in X chromosome inactivation

1991 ◽  
Vol 58 (1) ◽  
pp. 63-65 ◽  
Author(s):  
Deborah J. Fowlis ◽  
John D. Ansell ◽  
H. Spedding Micklem
Keyword(s):  
X Chromosome ◽  
Reciprocal Cross ◽  
Phosphoglycerate Kinase ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation

SummaryUsing mice that were mosaics for both Xce and phosphoglycerate kinase (Pgk-1) alleles, we present further evidence that the parental source of the X chromosome may affect the probability of that X chromosome remaining active. The reciprocal cross differences in PGK-1 activity described here are intermediate between those published previously for other alleles of Xce.

scholarly journals The Relationship Between Skewed X Chromosome Inactivation and the Prognosis of Graves' and Hashimoto's Diseases

Thyroid ◽  
2015 ◽  
Vol 25 (2) ◽  
pp. 256-261 ◽  
Author(s):  
Naoko Ishido ◽  
Naoya Inoue ◽  
Mikio Watanabe ◽  
Yoh Hidaka ◽  
Yoshinori Iwatani
Keyword(s):  
X Chromosome ◽  
X Chromosome Inactivation ◽  
Chromosome Inactivation ◽  
The Relationship ◽  
Skewed X Chromosome Inactivation
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