scholarly journals Genome-Wide Analysis of DNA Methylation in Buccal Cells of Children Conceived through IVF and ICSI

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1912
Author(s):  
Bastien Ducreux ◽  
Jean Frappier ◽  
Céline Bruno ◽  
Abiba Doukani ◽  
Magali Guilleman ◽  
...  

Early life periconceptional exposures during assisted reproductive technology (ART) procedures could alter the DNA methylation profiles of ART children, notably in imprinted genes and repetitive elements. At the genome scale, DNA methylation differences have been reported in ART conceptions at birth, but it is still unclear if those differences remain at childhood. Here, we performed an epigenome-wide DNA methylation association study using Illumina InfiniumEPIC BeadChip to assess the effects of the mode of conception on the methylome of buccal cells from 7- to 8-year-old children (48 children conceived after ART or naturally (control, CTL)) and according to the embryo culture medium in which they were conceived. We identified 127 differentially methylated positions (DMPs) and 16 differentially methylated regions (DMRs) (FDR < 0.05) with low delta beta differences between the two groups (ART vs. CTL). DMPs were preferentially located inside promoter proximal regions and CpG islands and were mostly hypermethylated with ART. We highlighted that the use of distinct embryo culture medium was not associated with DNA methylation differences in childhood. Overall, we bring additional evidence that children conceived via ART display limited genome-wide DNA methylation variation compared with those conceived naturally.

2020 ◽  
Vol 35 (3) ◽  
pp. 516-528
Author(s):  
Callista L Mulder ◽  
Tess M Wattimury ◽  
Aldo Jongejan ◽  
Cindy M de Winter-Korver ◽  
Saskia K M van Daalen ◽  
...  

Abstract Study question Is there a difference in DNA methylation status of imprinted genes in placentas derived from IVF conceptions where embryo culture was performed in human tubal fluid (HTF) versus G5 culture medium? Summary answer We found no statistically significant differences in the mean DNA methylation status of differentially methylated regions (DMRs) associated with parentally imprinted genes in placentas derived from IVF conceptions cultured in HTF versus G5 culture medium. What is known already Animal studies indicate that the embryo culture environment affects the DNA methylation status of the embryo. In humans, birthweight is known to be affected by the type of embryo culture medium used. The effect of embryo culture media on pregnancy, birth and child development may thus be mediated by differential methylation of parentally imprinted genes in the placenta. Study design, size, duration To identify differential DNA methylation of imprinted genes in human placenta derived from IVF conceptions exposed to HTF or G5 embryo culture medium, placenta samples (n = 43 for HTF, n = 54 for G5) were collected between 2010 and 2012 s as part of a multi-center randomized controlled trial in the Netherlands comparing these embryo culture media. Placenta samples from 69 naturally conceived (NC) live births were collected during 2008–2013 in the Netherlands as reference material. Participants/materials, setting, methods To identify differential DNA methylation of imprinted genes, we opted for an amplicon-based sequencing strategy on an Illumina MiSeq sequencing platform. DNA was isolated and 34 DMRs associated with well-defined parentally imprinted genes were amplified in a two-step PCR before sequencing using MiSeq technology. Sequencing data were analyzed in a multivariate fashion to eliminate possible confounding effects. Main results and the role of chance We found no statistically significant differences in the mean DNA methylation status of any of the imprinted DMRs in placentas derived from IVF conceptions cultured in HTF or G5 culture medium. We also did not observe any differences in the mean methylation status per amplicon nor in the variance in methylation per amplicon between the two culture medium groups. A separate surrogate variable analysis also demonstrated that the IVF culture medium was not associated with the DNA methylation status of these DMRs. The mean methylation level and variance per CpG was equal between HTF and G5 placenta. Additional comparison of DNA methylation status of NC placenta samples revealed no statistically significant differences in mean amplicon and CpG methylation between G5, HTF and NC placenta; however, the number of placenta samples exhibiting outlier methylation levels was higher in IVF placenta compared to NC (P &lt; 0.00001). Also, we were able to identify 37 CpG sites that uniquely displayed outlier methylation in G5 placentas and 32 CpG sites that uniquely displayed outlier methylation in HTF. In 8/37 (G5) and 4/32 (HTF) unique outliers CpGs, a medium-specific unique outlier could be directly correlated to outlier methylation of the entire amplicon. Limitations, reasons for caution Due to practical reasons, not all placentas were collected during the trial, and we collected the placentas from natural conceptions from a different cohort, potentially creating bias. We limited ourselves to the DNA methylation status of 34 imprinted DMRs, and we studied only the placenta and no other embryo-derived tissues. Wider implications of the findings It has often been postulated, but has yet to be rigorously tested, that imprinting mediates the effects of embryo culture conditions on pregnancy, birth and child development in humans. Since we did not detect any statistically significant effects of embryo culture conditions on methylation status of imprinted genes in the placenta, this suggests that other unexplored mechanisms may underlie these effects. The biological and clinical relevance of detected outliers with respect to methylation levels of CpGs and DMR require additional analysis in a larger sample size as well. Given the importance and the growing number of children born through IVF, research into these molecular mechanisms is urgently needed. Study funding/competing interest(s) This study was funded by the March of Dimes grant number #6-FY13-153. The authors have no conflicts of interest. Trial registration number Placental biopsies were obtained under Netherlands Trial Registry number 1979 and 1298.


2013 ◽  
Vol 42 (5) ◽  
pp. 2893-2905 ◽  
Author(s):  
Chunjing Bian ◽  
Xiaochun Yu

Abstract Ten-eleven translocation (TET) family enzymes convert 5-methylcytosine to 5-hydroxylmethylcytosine. However, the molecular mechanism that regulates this biological process is not clear. Here, we show the evidence that PGC7 (also known as Dppa3 or Stella) interacts with TET2 and TET3 both in vitro and in vivo to suppress the enzymatic activity of TET2 and TET3. Moreover, lacking PGC7 induces the loss of DNA methylation at imprinting loci. Genome-wide analysis of PGC7 reveals a consensus DNA motif that is recognized by PGC7. The CpG islands surrounding the PGC7-binding motifs are hypermethylated. Taken together, our study demonstrates a molecular mechanism by which PGC7 protects DNA methylation from TET family enzyme-dependent oxidation.


2020 ◽  
Vol 48 (15) ◽  
pp. 8431-8444 ◽  
Author(s):  
Byungkuk Min ◽  
Jung Sun Park ◽  
Young Sun Jeong ◽  
Kyuheum Jeon ◽  
Yong-Kook Kang

Abstract Genome-wide passive DNA demethylation in cleavage-stage mouse embryos is related to the cytoplasmic localization of the maintenance methyltransferase DNMT1. However, recent studies provided evidences of the nuclear localization of DNMT1 and its contribution to the maintenance of methylation levels of imprinted regions and other genomic loci in early embryos. Using the DNA adenine methylase identification method, we identified Dnmt1-binding regions in four- and eight-cell embryos. The unbiased distribution of Dnmt1 peaks in the genic regions (promoters and CpG islands) as well as the absence of a correlation between the Dnmt1 peaks and the expression levels of the peak-associated genes refutes the active participation of Dnmt1 in the transcriptional regulation of genes in the early developmental period. Instead, Dnmt1 was found to associate with genomic retroelements in a greatly biased fashion, particularly with the LINE1 (long interspersed nuclear elements) and ERVK (endogenous retrovirus type K) sequences. Transcriptomic analysis revealed that the transcripts of the Dnmt1-enriched retroelements were overrepresented in Dnmt1 knockdown embryos. Finally, methyl-CpG-binding domain sequencing proved that the Dnmt1-enriched retroelements, which were densely methylated in wild-type embryos, became demethylated in the Dnmt1-depleted embryos. Our results indicate that Dnmt1 is involved in the repression of retroelements through DNA methylation in early mouse development.


2019 ◽  
Vol 111 (4) ◽  
pp. 753-762.e1 ◽  
Author(s):  
Bo Liang ◽  
Yuan Gao ◽  
Jiabao Xu ◽  
Yizhi Song ◽  
Liming Xuan ◽  
...  

2012 ◽  
Vol 188 (4S) ◽  
pp. 1450-1456 ◽  
Author(s):  
Shweta Choudhry ◽  
Archana Deshpande ◽  
Liang Qiao ◽  
Kenneth Beckman ◽  
Saunak Sen ◽  
...  

2020 ◽  
Vol 32 (2) ◽  
pp. 166
Author(s):  
C. Aguilera ◽  
D. Veraguas ◽  
C. Henriquez ◽  
A. Velasquez ◽  
F. O. Castro ◽  
...  

Noninvasive methods are the clue to increase the efficiency of invitro-derived embryo selection without decreasing their competence. Embryos selection based on their morphology is the most used method but only 40% of selected embryos are able to implant and develop correctly. In humans, pre-implantation genetic diagnosis increases the efficiency of selection by excluding embryos with chromosomal abnormalities. However, pre-implantation genetic diagnosis needs embryonic cells, which might compromise embryo viability. On the other hand, embryos release extracellular vesicles (EVs: microvesicles and exosomes) to the culture medium that contain biological cargo-like proteins and mRNA lipids, and might contain genomic DNA (gDNA). For this study we evaluated the culture medium from embryos generated by intracytoplasmic sperm injection in a certified fertility clinic. Embryos were cultured in Global Total serum-free medium. The embryos were assessed at Day 3 of development and classified in three categories: top, fair, and poor quality. Corresponding medium was collected for isolation of EVs. The nature of EVs was confirmed by their size and concentration using nanoparticle tracking analysis (NTA), presence of surface markers (CD9, CD63, CD81, and CD40L), and morphology using transmission electron microscopy. A correlation analysis between NTA results (EV size and concentration) and embryo quality was performed. To evaluate chromosomal abnormalities of gDNA present in isolated EVs from embryo culture medium, microarray-based comparative genomic hybridization (aCGH) assay was performed. In a second experiment, aCGH analysis was performed and compared between arrested embryos and EVs isolated from corresponding culture medium. Isolated nanoparticles from embryo culture medium were positive to all markers CD9 (30.9%), CD63 (27.2%), CD81 (31.7%), CD40L (8.7%) and had a morphology accordingly to exosomes. The analysis of NTA data indicated that top-quality embryos had EVs with higher diameter (mean: 112.17nm, mode: 91.74nm) than embryos classified as fair (mean: 108.02nm, mode: 89.67nm) and poor quality (mean: 102.78nm, mode: 88.17 nm; P&lt;0.05). The aCGH analysis showed the representation of the 23 pairs of chromosomes in EVs from culture medium and the chromosomal abnormalities were detected in chromosome 4 (C4: 6/15 (40%)) and chromosome 13 (C13: 6/15 (40%)). In the second experiment, the aCGH assay also showed abnormalities in different chromosomes from samples of EVs from culture medium (24.9%) and were more frequent than those observed in the arrested embryos (8.7%; P=0.03). However, the rate of similitude in chromosomal abnormalities between EVs and their respective embryo was 70-80%. In conclusion, the size and gDNA of EVs from culture medium might be an alternative to evaluate the competence of human embryos. This research was supported by FONDECYT-1170310 and Corfo 17Cote-72437, Chile.


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