Linked Life Data

6957717

Source:http://linkedlifedata.com/resource/pubmed/id/6957717

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5886
pubmed:dateCreated
1982-12-16
pubmed:abstractText
The X chromosome in mammalian somatic cells is subject to unique regulation--usually genes on a single X chromosome are expressed while those on other X chromosomes are inactivated. The X-locus for steroid sulphatase (STS; EC 3.1.6.2), the microsomal enzyme that catalyses the hydrolysis of various 3 beta-hydroxysteroid sulphates, is exceptional because it seems to escape inactivation. Evidence for this comes from fibroblast clones in females heterozygous for mutations that result in a severe deficiency of this enzyme in affected males; all clones from these heterozygotes have STS activity, and enzyme-deficient clones that are expected if the locus were subject to inactivation, have not been found. Further evidence that the STS locus escapes inactivation is that the human inactive X chromosomes contributes STS activity to mouse-human hybrid cells. On the basis of these hybrid studies the STS locus has been mapped to the distal half of the short arm (p22-pter) of the human X chromosome. Although the STS locus on both X chromosomes in human female cells is expressed, quantitative measurements of STS activity in males and females do not accurately reflect the sex differences in number of X chromosomes (Table 1). The ratio of mean values for normal females to that of normal males is greater than 1:1 but less than the ratio of 2:1 expected if STS loci on all X chromosomes were equally expressed. The incomplete dosage effect suggests that the STS locus on the inactive X chromosome might not be fully expressed. To test this hypothesis, we examine two heterozygotes for X-linked STS deficiency who were also heterozygous for the common electrophoretic variants of glucose-6-phosphate dehydrogenase (G6PD A and B). Studies of fibroblast clones from these females provide evidence, presented here, for differential expression of STS loci on the active and inactive X chromosome.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0028-0836
pubmed:author
pubmed:issnType
Print
pubmed:day
28
pubmed:volume
299
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
838-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1982
pubmed:articleTitle
Differential expression of steroid sulphatase locus on active and inactive human X chromosome.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't