Amy M Inkster, Allison M Matthews, Tanya N Phung, Seema B Plaisier, Melissa A Wilson, Carolyn J Brown, Wendy P Robinson
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引用次数: 0
Abstract
Background: The human placenta is distinct from most organs due to its uniquely low-methylated genome. DNA methylation (DNAme) is particularly depleted in the placenta at partially methylated domains and on the inactive X chromosome (Xi) in XX samples. While Xi DNAme is known to be critical for X-chromosome inactivation (XCI) in other tissues, its role in the placenta remains unclear. Understanding X-linked DNAme variation in the placenta may provide insights into XCI and have implications for prenatal development and phenotypic sex differences.
Methods: DNAme data were analyzed from over 350 human placental (chorionic villus) samples, along with samples from cord blood, amnion and chorion placental membranes, and fetal somatic tissues. We characterized X chromosome DNAme variation in the placenta relative to sample variables including cell composition, ancestry, maternal age, placental weight, and fetal birth weight, and compared these patterns to other tissues. We also evaluated the relationship between X-linked DNAme and previously reported XCI gene expression status in placenta.
Results: Our findings confirm that the placenta exhibits significant depletion of DNAme on the Xi compared to other tissues. Additionally, we observe that X chromosome DNAme profiles in the placenta are influenced by cell composition, particularly trophoblast proportion, with minimal DNAme variation across gestation. Notably, low promoter DNAme is observed at most genes on the Xi regardless of XCI status, challenging known associations in somatic tissues between low promoter DNAme and escape from XCI.
Conclusions: This study provides evidence that the human placenta has a distinct Xi DNAme landscape, which may inform our understanding of sex differences during prenatal development. Future research should explore the mechanisms underlying the placenta's unique X-linked DNAme profile, and the factors involved in placental XCI maintenance.
期刊介绍：
Biology of Sex Differences is a unique scientific journal focusing on sex differences in physiology, behavior, and disease from molecular to phenotypic levels, incorporating both basic and clinical research. The journal aims to enhance understanding of basic principles and facilitate the development of therapeutic and diagnostic tools specific to sex differences. As an open-access journal, it is the official publication of the Organization for the Study of Sex Differences and co-published by the Society for Women's Health Research.
Topical areas include, but are not limited to sex differences in: genomics; the microbiome; epigenetics; molecular and cell biology; tissue biology; physiology; interaction of tissue systems, in any system including adipose, behavioral, cardiovascular, immune, muscular, neural, renal, and skeletal; clinical studies bearing on sex differences in disease or response to therapy.
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