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Updated: Jun 22, 2025
Minimally Invasive Embryo Transfer and Embryo Vitrification at the Optimal Embryo Stage in Rabbit Model
Published on: May 16, 2019
Vitrification of pig embryos dysregulates the microRNA transcriptome profile
Cristina Cuello1, Alejandro González-Plaza1, Josep M Cambra2
1Department of Medicine and Animal Surgery, Faculty of Veterinary Medicine, International Excellence Campus for Higher Education and Research "Campus Mare Nostrum", Institute for Biomedical Research of Murcia (IMIB-Arrixaca), University of Murcia, 30100, Murcia, Spain.
Abstract:
This study examined how the vitrification of pig blastocysts using either the superfine open pulled straw (SOPS) or Cryotop method affects the expression profile of embryonic microRNA (miRNA) transcriptomes, as well as its relation to changes in the expression of target genes (TGs). Surgically collected pig blastocysts were vitrified using either the SOPS method (n = 60; 4-6 embryos/device) or the Cryotop system (n = 60; 20 embryos/device). Embryos were cultured in vitro for 24 h after warming. Fresh blastocysts (n = 60) cultured for 24 h served as controls. After in vitro culture, five pools of eight viable blastocysts from each group were prepared for miRNA expression analysis based on a microarray approach. Then, biological interpretation of miRNAs profiles and integrative analysis of miRNA and mRNA transcriptome data were performed. Survival after 24 h of in vitro culture was similar (>96 %) for both the vitrification systems and the control group (100 %). Compared with the controls, the SOPS-vitrified blastocysts had 94 (one upregulated and 93 downregulated) differentially expressed (DE) miRNAs, and the Cryotop-vitrified blastocysts had 174 DE miRNAs (one upregulated and 173 downregulated). One DE miRNA (miR-503) in the SOPS group and three DE miRNAs (miR-7139-3p, miR-214 and miR-885-3p) in the Cryotop group were annotated for Sus scrofa. The integrative analysis showed that 27 and 61 DE TGs were regulated by the DE miRNAs in blastocysts vitrified with the SOPS and Cryotop systems, respectively. The TGs enriched one pathway (the TGF-β signaling pathway) for the SOPS system and four pathways (HIF-1, Notch, ascorbate and aldarate metabolism and glycosphingolipid biosynthesis-ganglio series) for the Cryotop system. In summary, vitrification via the SOPS and Cryotop systems dysregulates miRNAs, with slight differences between methods. The altered miRNAs identified in this study were related mainly to cell proliferation, apoptosis, and the response to cell stress. Further studies are needed to clarify the consequences of dysregulation of miRNAs involved in the TGF-β (SOPS-vitrified blastocyst) and Notch (Cryotop-vitrified blastocyst) signaling pathways, particularly if they can affect embryonic development.
Insights
Vitrification of pig blastocysts using SOPS or Cryotop methods alters microRNA (miRNA) expression, impacting target genes and cellular processes like proliferation and apoptosis. Differences exist between the two vitrification techniques.
Area of Science:
- Reproductive Biology
- Developmental Biology
- Molecular Biology
Background:
- Vitrification is a key cryopreservation technique for embryos.
- Understanding the molecular impact of different vitrification methods is crucial for optimizing assisted reproductive technologies.
- MicroRNAs (miRNAs) play vital roles in regulating gene expression during embryonic development.
Purpose of the Study:
- To compare the effects of superfine open pulled straw (SOPS) and Cryotop vitrification methods on pig blastocyst miRNA transcriptomes.
- To investigate the relationship between altered miRNA expression and changes in target gene (TG) expression post-vitrification.
- To identify specific molecular pathways affected by vitrification-induced miRNA dysregulation.
Main Methods:
- Pig blastocysts were vitrified using SOPS or Cryotop methods and cultured in vitro.
- MicroRNA expression profiling was performed using microarrays.
- Integrative analysis of miRNA and mRNA transcriptome data was conducted to identify differentially expressed genes and pathways.
Main Results:
- Both SOPS and Cryotop vitrification significantly altered miRNA expression profiles compared to controls.
- Cryotop vitrification resulted in a greater number of differentially expressed miRNAs (174) than SOPS (94).
- Vitrification affected target genes involved in pathways such as TGF-β signaling (SOPS) and Notch signaling (Cryotop).
Conclusions:
- Vitrification using SOPS and Cryotop methods induces miRNA dysregulation in pig blastocysts, with method-specific differences.
- Altered miRNAs are primarily associated with cell proliferation, apoptosis, and stress response.
- Further research is needed to elucidate the impact of TGF-β and Notch pathway alterations on embryonic development.
