X-chromosome inactivation in the human trophoblast of early pregnancy

X-chromosome inactivation in the human trophoblast of early pregnancy

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ABSTRACT To investigate X-chromosome inactivation (XCI) in human trophoblasts during early pregnancy, tropho-blast genomic DNA was extracted and analyzed for a _Bst XI_ restriction endonuclease site polymorphism in the X-linked phosphoglycerate kinase gene, after digestion with methylation-sensitive _Hpa II_ (control samples were digested instead with _Afa I_). Six villous trophoblast DNA samples were informative for the polymorphism (ie, heterozygous) and were derived from women homozygous for the polymorphism. These samples were then evaluated for XCI. In five of the six samples with _Hpa II_ predigestion, the sizes of the two heterozygous band peaks differed; maternal X-chromosome (XM)-derived alleles showed smaller peak sizes than paternal X-chromosome (XP)-derived alleles, but the differences varied in degree. In samples obtained by microdissection from formalin-fixed, paraffin-embedded tissues (30 samples from different anchoring villi, and 38 samples from different branch villi), monoclonal band patterns of XP-derived alleles were observed more frequently than those of XM-derived alleles, but almost half of the samples showed polyclonal pat-terns. Our results suggest that a skewing of XCI exists in the human trophoblast; however, the degree of non-randomness due to predominant XP inactivation appears to be restricted. It is probable that transcription of the X inactivation center (_XIC_) begins earlier in mice than in humans. SIMILAR CONTENT BEING VIEWED BY OTHERS INHERENT MOSAICISM AND EXTENSIVE MUTATION OF HUMAN PLACENTAS Article 10 March 2021 PREVALENCE OF CHROMOSOMAL ALTERATIONS IN FIRST-TRIMESTER SPONTANEOUS PREGNANCY LOSS Article Open access 23 November 2023 CHARACTERISTIC DNA METHYLATION PROFILES OF CHORIONIC VILLI IN RECURRENT MISCARRIAGE Article Open access 27 July 2022 ARTICLE PDF AUTHOR INFORMATION AUTHORS AND AFFILIATIONS * Department of Obstetrics and Gynecology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan Tel. +81-22-717-7251; Fax +81-22-717-7258 e-mail: uehara@ob-gy.med.tohoku.ac.jp, Japan S. Uehara, M. Tamura, N. Yaegashi, K. Okamura & A. Yajima * Department of Forensic Medicine, Tohoku University School of Medicine, Sendai 980-8574, Japan, Japan M. Nata & G. Ji Authors * S. Uehara View author publications You can also search for this author inPubMed Google Scholar * M. Tamura View author publications You can also search for this author inPubMed Google Scholar * M. Nata View author publications You can also search for this author inPubMed Google Scholar * G. Ji View author publications You can also search for this author inPubMed Google Scholar * N. Yaegashi View author publications You can also search for this author inPubMed Google Scholar * K. Okamura View author publications You can also search for this author inPubMed Google Scholar * A. Yajima View author publications You can also search for this author inPubMed Google Scholar ADDITIONAL INFORMATION Received: October 14, 1999 / Accepted: December 3, 1999 RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Uehara, S., Tamura, M., Nata, M. _et al._ X-chromosome inactivation in the human trophoblast of early pregnancy. _J Hum Genet_ 45, 119–126 (2000). https://doi.org/10.1007/s100380050197 Download citation * Published: 01 May 2000 * Issue Date: May 2000 * DOI: https://doi.org/10.1007/s100380050197 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get shareable link Sorry, a shareable link is not currently available for this article. Copy to clipboard Provided by the Springer Nature SharedIt content-sharing initiative * Key words Extra-embryonic tissue * Methylation-sensitive endonuclease * Phosphoglycerate kinase * RFLP * Skewing of X-chromosome inactivation

ABSTRACT To investigate X-chromosome inactivation (XCI) in human trophoblasts during early pregnancy, tropho-blast genomic DNA was extracted and analyzed for a _Bst XI_ restriction


endonuclease site polymorphism in the X-linked phosphoglycerate kinase gene, after digestion with methylation-sensitive _Hpa II_ (control samples were digested instead with _Afa I_). Six


villous trophoblast DNA samples were informative for the polymorphism (ie, heterozygous) and were derived from women homozygous for the polymorphism. These samples were then evaluated for


XCI. In five of the six samples with _Hpa II_ predigestion, the sizes of the two heterozygous band peaks differed; maternal X-chromosome (XM)-derived alleles showed smaller peak sizes than


paternal X-chromosome (XP)-derived alleles, but the differences varied in degree. In samples obtained by microdissection from formalin-fixed, paraffin-embedded tissues (30 samples from


different anchoring villi, and 38 samples from different branch villi), monoclonal band patterns of XP-derived alleles were observed more frequently than those of XM-derived alleles, but


almost half of the samples showed polyclonal pat-terns. Our results suggest that a skewing of XCI exists in the human trophoblast; however, the degree of non-randomness due to predominant XP


inactivation appears to be restricted. It is probable that transcription of the X inactivation center (_XIC_) begins earlier in mice than in humans. SIMILAR CONTENT BEING VIEWED BY OTHERS


INHERENT MOSAICISM AND EXTENSIVE MUTATION OF HUMAN PLACENTAS Article 10 March 2021 PREVALENCE OF CHROMOSOMAL ALTERATIONS IN FIRST-TRIMESTER SPONTANEOUS PREGNANCY LOSS Article Open access 23


November 2023 CHARACTERISTIC DNA METHYLATION PROFILES OF CHORIONIC VILLI IN RECURRENT MISCARRIAGE Article Open access 27 July 2022 ARTICLE PDF AUTHOR INFORMATION AUTHORS AND AFFILIATIONS *


Department of Obstetrics and Gynecology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan Tel. +81-22-717-7251; Fax +81-22-717-7258 e-mail:


[email protected], Japan S. Uehara, M. Tamura, N. Yaegashi, K. Okamura & A. Yajima * Department of Forensic Medicine, Tohoku University School of Medicine, Sendai 980-8574,


Japan, Japan M. Nata & G. Ji Authors * S. Uehara View author publications You can also search for this author inPubMed Google Scholar * M. Tamura View author publications You can also


search for this author inPubMed Google Scholar * M. Nata View author publications You can also search for this author inPubMed Google Scholar * G. Ji View author publications You can also


search for this author inPubMed Google Scholar * N. Yaegashi View author publications You can also search for this author inPubMed Google Scholar * K. Okamura View author publications You


can also search for this author inPubMed Google Scholar * A. Yajima View author publications You can also search for this author inPubMed Google Scholar ADDITIONAL INFORMATION Received:


October 14, 1999 / Accepted: December 3, 1999 RIGHTS AND PERMISSIONS Reprints and permissions ABOUT THIS ARTICLE CITE THIS ARTICLE Uehara, S., Tamura, M., Nata, M. _et al._ X-chromosome


inactivation in the human trophoblast of early pregnancy. _J Hum Genet_ 45, 119–126 (2000). https://doi.org/10.1007/s100380050197 Download citation * Published: 01 May 2000 * Issue Date: May


2000 * DOI: https://doi.org/10.1007/s100380050197 SHARE THIS ARTICLE Anyone you share the following link with will be able to read this content: Get shareable link Sorry, a shareable link


is not currently available for this article. Copy to clipboard Provided by the Springer Nature SharedIt content-sharing initiative * Key words Extra-embryonic tissue * Methylation-sensitive


endonuclease * Phosphoglycerate kinase * RFLP * Skewing of X-chromosome inactivation