Epigenetic modifications during oocyte growth correlates with extended parthenogenetic development in the mouse

1996 ◽  
Vol 13 (1) ◽  
pp. 91-94 ◽  
Author(s):  
Tomohiro Kono ◽  
Yayoi Obata ◽  
Tomomi Yoshimzu ◽  
Tatsuo Nakahara ◽  
John Carroll
Keyword(s):  
Epigenetic Modifications ◽  
Oocyte Growth ◽  
Parthenogenetic Development

Disruption of primary imprinting during oocyte growth leads to the modified expression of imprinted genes during embryogenesis

Development ◽  
1998 ◽  
Vol 125 (8) ◽  
pp. 1553-1560 ◽  
Author(s):  
Y. Obata ◽  
T. Kaneko-Ishino ◽  
T. Koide ◽  
Y. Takai ◽  
T. Ueda ◽  
...  
Keyword(s):  
Epigenetic Modifications ◽  
The Other ◽  
Imprinted Genes ◽  
Oocyte Growth ◽  
Parthenogenetic Development ◽  
Crucial Effect ◽  
H19 Gene ◽  
Parthenogenetic Embryos

Parthenogenetic embryos, which contained one genome from a neonate-derived non-growing oocyte and the other from a fully grown oocyte, developed to day 13.5 of gestation in mice, 3 days longer than previously recorded for parthenogenetic development. To investigate the hypothesis that disruption of primary imprinting during oocyte growth leads to the modified expression of imprinted genes and this parthenogenetic phenotype, we have examined Peg1/Mest, Igf2, Peg3, Snrpn, H19, Igf2r and excess p57KIP2. We show that paternally expressed genes, Peg1/Mest, Peg3 and Snrpn, are expressed in the parthenotes, presumably due to a lack of maternal epigenetic modifications during oocyte growth. In contrast, the expression of Igf2, which is repressed in a competitive manner by transcription of the H19 gene, was very low. Furthermore, we show that the maternally expressed Igf2r and p57KIP2 genes were repressed in the alleles of the non-growing oocyte indicating maternal modifications during oocyte growth are necessary for its expression. Thus, our results show that primary imprinting during oocyte growth exhibits a crucial effect on both the expression and repression of maternal alleles during embryogenesis.

scholarly journals Alterations in epigenetic modifications during oocyte growth in mice

Reproduction ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Shun-ichiro Kageyama ◽  
Honglin Liu ◽  
Naoto Kaneko ◽  
Masatoshi Ooga ◽  
Masao Nagata ◽  
...  
Keyword(s):  
Gene Expression ◽  
Histone Modifications ◽  
Epigenetic Modification ◽  
Germinal Vesicle ◽  
Epigenetic Modifications ◽  
Condensed Chromatin ◽  
Rt Pcr ◽  
Oocyte Growth ◽  
Lysine Residues ◽  
Signal Intensities

During oocyte growth, chromatin structure is altered globally and gene expression is silenced. To investigate the involvement of epigenetic modifications in the regulation of these phenomena, changes in global DNA methylation and in various histone modifications, i.e. acetylation of H3K9, H3K18, H4K5, and H4K12, and methylation of H3K4 and H3K9, were examined during the growth of mouse oocytes. Immunocytochemical analysis revealed that the signal intensities of all these modifications increased during growth and that fully grown, germinal vesicle (GV)-stage oocytes showed the most modifications. Since acetylation of most of the lysine residues on histones and methylation of H3K4 are associated with active gene expression, the increased levels of these modifications do not seem to be associated with gene silencing in GV-stage oocytes. Given that there are two types of GV-stage oocytes with different chromatin configurations and transcriptional activities, the epigenetic modification statuses of these two types were compared. The levels of all the epigenetic modifications examined were higher in the SN(surrounded nucleolus)-type oocytes, in which highly condensed chromatin is concentrated in the area around the nucleolus and gene expression is silenced than in the NSN(not surrounded nucleolus)-type oocytes, in which less-condensed chromatin does not surround the nucleolus and gene expression is active. In addition, the expression levels of various enzymes that catalyze histone modifications were shown by RT-PCR to increase with oocyte growth. Taken together, the results show that all of the epigenetic modifications increased in a concerted manner during oocyte growth, and suggest that these increases are not associated with gene expression.

Genetic modification for bimaternal embryo development

2009 ◽  
Vol 21 (1) ◽  
pp. 31 ◽  
Author(s):  
Tomohiro Kono
Keyword(s):  
Embryo Development ◽  
Genetic Modification ◽  
Direct Evidence ◽  
Epigenetic Modification ◽  
Growth Period ◽  
Epigenetic Modifications ◽  
Imprinted Genes ◽  
Mammalian Development ◽  
Oocyte Growth ◽  
Paternal Contribution

Full mammalian development typically requires genomes from both the oocyte and spermatozoon. Biparental reproduction is necessary because of parent-specific epigenetic modification of the genome during gametogenesis; that is, a maternal methylation imprint imposed during the oocyte growth period and a paternal methylation imprint imposed in pregonadal gonocytes. This leads to unequivalent expression of imprinted genes from the maternal and paternal alleles in embryos and individuals. It is possible to hypothesise that the maternal methylation imprint is necessary to prevent parthenogenesis, which extinguishes the opportunity for having descendents, whereas the paternal methylation imprint prevents parthenogenesis, ensuring that a paternal contribution is obligatory for any descendants. To date, there are several lines of direct evidence that the epigenetic modifications that occur during oocyte growth have a decisive effect on mammalian development. Using bimaternal embryos with two sets of maternal genomes, the present paper illustrates how parental methylation imprints are an obstacle to the progression of parthenogenesis.

scholarly journals Epigenetic Modifications Necessary for Normal Development Are Established During Oocyte Growth in Mice1

2000 ◽  
Vol 62 (3) ◽  
pp. 616-621 ◽  
Author(s):  
Siqin Bao ◽  
Yayoi Obata ◽  
John Carroll ◽  
Ikuo Domeki ◽  
Tomohiro Kono
Keyword(s):  
Normal Development ◽  
Epigenetic Modifications ◽  
Oocyte Growth

Genome-wide reprogramming by DNA demethylation during mouse oocyte growth and early development

2014 ◽  
Author(s):  
Akihiko Sakashita ◽  
Yosuke Iseki ◽  
Mei Nakajima ◽  
Takuya Wakai ◽  
Hisato Kobayashi ◽  
...  
Keyword(s):  
Early Development ◽  
Dna Demethylation ◽  
Mouse Oocyte ◽  
Oocyte Growth ◽  
Genome Wide
Sign in / Sign up

Export Citation Format

Share Document