scholarly journals Methylation dynamics during folliculogenesis and early embryo development in sheep

Reproduction ◽  
2017 ◽  
Vol 153 (5) ◽  
pp. 605-619 ◽  
Author(s):  
Laura Masala ◽  
Giovanni Pietro Burrai ◽  
Emanuela Bellu ◽  
Federica Ariu ◽  
Luisa Bogliolo ◽  
...  

Genome-wide DNA methylation reprogramming occurs during mammalian gametogenesis and early embryogenesis. Post-fertilization demethylation of paternal and maternal genomes is considered to occur by an active and passive mechanism respectively, in most mammals but sheep; in this species no loss of methylation was observed in either pronucleus. Post-fertilization reprogramming relies on methylating and demethylating enzymes and co-factors that are stored during oocyte growth, concurrently with the re-methylation of the oocyte itself. The crucial remodelling of the oocyte epigenetic baggage often overlaps with potential interfering events such as exposure to assisted reproduction technologies or environmental changes. Here, we report a temporal analysis of methylation dynamics during folliculogenesis and early embryo development in sheep. We characterized global DNA methylation and hydroxymethylation by immunofluorescence and relatively quantified the expression of the enzymes and co-factors mainly responsible for their remodelling (DNA methyltransferases (DNMTs), ten-eleven translocation (TET) proteins and methyl-CpG-binding domain (MBD) proteins). Our results illustrate for the first time the patterns of hydroxymethylation during oocyte growth. We observed different patterns of methylation and hydroxymethylation between the two parental pronuclei, suggesting that male pronucleus undergoes active demethylation also in sheep. Finally, we describe gene-specific accumulation dynamics for methylating and demethylating enzymes during oocyte growth and observe patterns of expression associated with developmental competence in a differential model of oocyte potential. Our work contributes to the understanding of the methylation dynamics during folliculogenesis and early embryo development and improves the overall picture of early rearrangements that will originate the embryo epigenome.

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2358
Author(s):  
Katarzyna Suwik ◽  
Emilia Sinderewicz ◽  
Dorota Boruszewska ◽  
Ilona Kowalczyk-Zięba ◽  
Joanna Staszkiewicz-Chodor ◽  
...  

Peroxisome proliferator-activated receptors (PPARs), a nuclear receptors for prostacyclin (PGI2) have been recognized as being essential for early embryo development. The objectives of the present study were to determine if the bovine early- and late-cleaved embryos in different stages of early development express PPARγ and PPARδ. Since embryo developmental competence depends on numerous biological factors, we evaluated if the expression of PPARγ and PPARδ correlate with selected embryo quality markers (SOX2, OCT4, PLAC8, IGF1R) in the in vitro produced embryos at different stages of their development. Developmental rates and embryo quality for early- and late-cleaved embryos were provided according to International Embryo Transfer Society (IETS; developmental stages: 2-, 4-, 16-cell embryo, morula, blastocyst (1—early, 2—developing, 3—expanded, 4—hatched); quality stages: A—high quality, B—moderate quality, C—low quality). We found that bovine embryos expressed mRNA of PPARδ and PPARγ at all stages of early development, independently of their quality. In addition, the expression of PPARδ and PPARγ correlated with the expression of quality markers in bovine blastocysts. Positive correlations were stronger and more frequent in the group of early-cleaved embryos, whereas the negative correlations were typical for the group of late-cleaved embryos. Obtained results and available literature reports may indicate the participation of PGI2, via PPARδ and PPARγ, in the processes related to the early embryo development, through the participation of this factor in the modulation of blastocyst hatching, implantation, and post-implantation development.


2019 ◽  
Vol 513 (4) ◽  
pp. 912-918 ◽  
Author(s):  
Li-Hua Fan ◽  
Zhen-Bo Wang ◽  
Qian-Nan Li ◽  
Tie-Gang Meng ◽  
Ming-Zhe Dong ◽  
...  

Epigenetics ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. 568-588 ◽  
Author(s):  
Anelise Dos Santos Mendonça ◽  
Márcia Marques Silveira ◽  
Álvaro Fabrício Lopes Rios ◽  
Paula Magnelli Mangiavacchi ◽  
Alexandre Rodrigues Caetano ◽  
...  

2018 ◽  
Vol 60 (4) ◽  
pp. 197-204 ◽  
Author(s):  
Zhiren Zhang ◽  
Yunqing Cao ◽  
Yanhui Zhai ◽  
Xiaoling Ma ◽  
Xinglan An ◽  
...  

2019 ◽  
Vol 16 (3) ◽  
pp. 465-474
Author(s):  
Mélanie Breton-Larrivée ◽  
Elizabeth Elder ◽  
Serge McGraw

2019 ◽  
Author(s):  
Isabel Gómez-Redondo ◽  
Priscila Ramos-Ibeas ◽  
Eva Pericuesta ◽  
Benjamín Planells ◽  
Raul Fernández-González ◽  
...  

2021 ◽  
Author(s):  
Zhen Sun ◽  
Hua Yu ◽  
Jing Zhao ◽  
Tianyu Tan ◽  
Hongru Pan ◽  
...  

AbstractLIN28 is an RNA binding protein with important roles in early embryo development, stem cell differentiation/reprogramming, tumorigenesis and metabolism. Previous studies have focused mainly on its role in the cytosol where it interacts with Let-7 microRNA precursors or mRNAs, and few have addressed LIN28’s role within the nucleus. Here, we show that LIN28 displays dynamic temporal and spatial expression during murine embryo development. Maternal LIN28 expression drops upon exit from the 2-cell stage, and zygotic LIN28 protein is induced at the forming nucleolus during 4-cell to blastocyst stage development, to become dominantly expressed in the cytosol after implantation. In cultured pluripotent stem cells (PSCs), loss of LIN28 led to nucleolar stress and activation of a 2-cell/4-cell-like transcriptional program characterized by the expression of endogenous retrovirus genes. Mechanistically, LIN28 binds to small nucleolar RNAs and rRNA to maintain nucleolar integrity, and its loss leads to nucleolar phase separation defects, ribosomal stress and activation of P53 which in turn binds to and activates 2C transcription factor Dux. LIN28 also resides in a complex containing the nucleolar factor Nucleolin (NCL) and the transcriptional repressor TRIM28, and LIN28 loss leads to reduced occupancy of the NCL/TRIM28 complex on the Dux and rDNA loci, and thus de-repressed Dux and reduced rRNA expression. Lin28 knockout cells with nucleolar stress are more likely to assume a slowly cycling, translationally inert and anabolically inactive state, which is a part of previously unappreciated 2C-like transcriptional program. These findings elucidate novel roles for nucleolar LIN28 in PSCs, and a new mechanism linking 2C program and nucleolar functions in PSCs and early embryo development.


2016 ◽  
Vol 27 (5) ◽  
pp. 768-775 ◽  
Author(s):  
Xue-Shan Ma ◽  
Fei Lin ◽  
Zhong-Wei Wang ◽  
Meng-Wen Hu ◽  
Lin Huang ◽  
...  

Geminin controls proper centrosome duplication, cell division, and differentiation. We investigated the function of geminin in oogenesis, fertilization, and early embryo development by deleting the geminin gene in oocytes from the primordial follicle stage. Oocyte-specific disruption of geminin results in low fertility in mice. Even though there was no evident anomaly of oogenesis, oocyte meiotic maturation, natural ovulation, or fertilization, early embryo development and implantation were impaired. The fertilized eggs derived from mutant mice showed developmental delay, and many were blocked at the late zygote stage. Cdt1 protein was decreased, whereas Chk1 and H2AX phosphorylation was increased, in fertilized eggs after geminin depletion. Our results suggest that disruption of maternal geminin may decrease Cdt1 expression and cause DNA rereplication, which then activates the cell cycle checkpoint and DNA damage repair and thus impairs early embryo development.


Sign in / Sign up

Export Citation Format

Share Document