2022  1,200
2021  1,540
2020  1,374
2019  1,023
2018  0,932
2017  0,977
2016  0,799
2015  0,662
2014  0,740
2013  0,739
2012  0,637
2011  0,658
2010  0,654
2009  0,570
2008  0,849
2007  0,805
2006  0,330
2005  0,435
2004  0,623
2003  0,567
2002  0,641
2001  0,490
2000  0,477
1999  0,762
1998  0,785
1997  0,507
1996  0,518
1995  0,502
Vol 49(2015) N 1 p. 144-152; DOI 10.1134/S0026893314060193 Full Text

S.A. Vasilyev1,2*, E.N. Tolmacheva1, A.A. Kashevarova1,2, E.A. Sazhenova1, I.N. Lebedev1,2

Methylation status of LINE-1 retrotransposon in chromosomal mosaicism during early stages of human embryonic development

1Research Institute of Medical Genetics, Siberian Branch, Russian Academy of Medical Sciences, Tomsk, 634050 Russia
2Laboratory of Human Ontogenetics, Tomsk State University, Tomsk, 634050 Russia
Received - 2014-05-23; Accepted - 2014-06-30

Early stages of human embryonic development are characterized by the spatiotemporal coincidence of events of total epigenetic genome reprogramming and elevated level of mosaic forms of numerical chromosome abnormalities. It is possible that the abnormal reprogramming of various regions of the genome can lead to violations of local epigenetic chromatin organization and gene expression, which affect the correct chromosome segregation during mitosis. In this study, a comparative analysis of the methylation index of LINE-1 retrotransposon, which largely reflects the methylation profile of the genome, is performed in placental tissues of spontaneous abortions with complete and mosaic forms of aneuploidy and with a normal karyotype, as well as in the control group of induced abortions of the first trimester of pregnancy. It was shown that extraembryonic mesoderm and chorionic cytotrophoblast of spontaneous abortions with chromosomal mosaicism are characterized by the highest index of LINE-1 methylation among all studied groups. At the same time, the excessive hypomethylation of transposable genetic element was registered in spontaneous abortions with normal karyotype. We hypothesize that violations of parental genome demethylation during epigenetic reprogramming at preimplantation stages of development may be associated with an increased frequency of mitotic errors in chromosome segregation, which leads to the formation of a mosaic karyotype.

LINE-1, aneuploidy, chromosomal mosaicism, epigenetic genome reprogramming