Incomplete X chromosome dosage compensation in chorionic villi of human placenta

Barbara R Migeon, S. F. Wolf, J. Axelman, D. C. Kaslow, M. Schmidt

Research output: Contribution to journalArticle

Abstract

Studies of glucose-6-phosphate dehydrogenase (G6PD) in heterozygous cells from chorionic villi of five fetal and one newborn placenta show that the locus on the allocyclic X is expressed in many cells of this trophectoderm derivative. Heterodimers were present in clonal populations of cells with normal diploid karyotype and a late replicating X chromosome. The expression of the two X chromosomes was unequal, based on ratios of homodimers and heterodimers in clones. Studies of DNA, digested with Hpa II and probed with cloned genomic G6PD sequences, indicate that expression of the locus in chorionic villi is associated with hypomethylation of 3' CpG clusters. These findings suggest that dosage compensation, at least at the G6PD locus, has not been well established or maintained (or both) in placental tissue. Furthermore, the active X chromosome in these human cells of trophoblastic origin can be either the paternal or maternal one; therefore, paternal X inactivation in extraembryonic lineages is not an essential feature of mammalian X dosage compensation.

Original languageEnglish (US)
Pages (from-to)3390-3394
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume82
Issue number10
DOIs
StatePublished - 1985

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Chorionic Villi
X Chromosome
Placenta
Glucosephosphate Dehydrogenase
Chromosomes, Human, X
X Chromosome Inactivation
CpG Islands
Diploidy
Karyotype
Clone Cells
Mothers
DNA
Population

ASJC Scopus subject areas

  • Genetics
  • General

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Incomplete X chromosome dosage compensation in chorionic villi of human placenta. / Migeon, Barbara R; Wolf, S. F.; Axelman, J.; Kaslow, D. C.; Schmidt, M.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 82, No. 10, 1985, p. 3390-3394.

Research output: Contribution to journalArticle

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AU - Wolf, S. F.

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AU - Kaslow, D. C.

AU - Schmidt, M.

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