Related Experiment Video
Updated: Jul 9, 2025
Transcriptome Profiling of In-Vivo Produced Bovine Pre-implantation Embryos Using Two-color Microarray Platform
Published on: January 30, 2017
MicroRNA-146b negatively affects bovine embryo development and quality
Krishna Chaitanya Pavani1,2, Guan XueFeng3, Jayendra Chunduru4
1Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, University of Ghent, Salisburylaan, Merelbeke, Belgium.
In Brief:
MicroRNAs (miRNAs) carried in extracellular vesicles are one of the essential factors for embryo development. This study demonstrates that miRNA-146 b has negative impacts on the quality and development of bovine embryos and also shows its higher expression in non-blastocyst embryos and related EVs.
Abstract:
MicroRNAs (miRNAs), which can be carried inside extracellular vesicles (EVs), play a crucial role in regulating embryo development up to the blastocyst stage. Yet, the molecular mechanisms underlying blastocyst development and quality are largely unknown. Recently, our group identified 69 differentially expressed miRNAs in extracellular vesicles (EVs) isolated from culture medium conditioned by bovine embryos that either developed to the blastocyst stage or did not (non-blastocysts). We found miR-146b to be more abundant in the EVs derived from media conditioned by non-blastocyst embryos. Using RT-qPCR, we here confirmed the upregulation of miR-146b in non-blastocyst (arrested at two- to four-cell and morula stage) embryos compared to blastocysts (P < 0.005), which coincides with the upregulation of miR-146b in EVs derived from the medium of these non-blastocysts. To evaluate a functional effect, bovine embryo culture media were supplemented with miR-146b mimics, resulting in significantly decreased embryo quality, with lower blastocyst rates at day 7 and lower total cell numbers, while the opposite was found after supplementation with miR-146b inhibitors, which resulted in reduced apoptosis rates (P < 0.01). Transcriptomic analysis of embryos treated with miR-146b mimics or inhibitors showed differential expression (P < 0.01) of genes associated with apoptosis, cell differentiation, and the RNA Pol II transcription complex, including WDR36, MBNL2, ERCC6l2, PYGO1, and SNIP1. Overall, miR-146b is overexpressed in non-blastocyst embryos and in EVs secreted by these embryos, and it regulates genes involved in embryo development and apoptosis, resulting in decreased embryo quality.
Insights
MicroRNAs (miRNAs) carried in extracellular vesicles (EVs) impact embryo development. Overexpressed miR-146b in non-blastocyst embryos and EVs reduces embryo quality and increases apoptosis, revealing a key regulatory mechanism.
Area of Science:
- Reproductive biology
- Molecular biology
- Developmental biology
Background:
- MicroRNAs (miRNAs) within extracellular vesicles (EVs) are vital for embryo development.
- Molecular mechanisms governing blastocyst development and quality remain largely undefined.
- Extracellular vesicles (EVs) secreted by bovine embryos contain differentially expressed miRNAs.
Purpose of the Study:
- To investigate the role of miR-146b in bovine embryo development and quality.
- To determine the functional impact of miR-146b on blastocyst formation and apoptosis.
- To identify genes regulated by miR-146b during early embryonic development.
Main Methods:
- RT-qPCR to quantify miR-146b expression in embryos and EVs.
- Supplementation of embryo culture media with miR-146b mimics and inhibitors.
- Transcriptomic analysis of treated embryos to assess gene expression changes.
Main Results:
- miR-146b was upregulated in non-blastocyst embryos and their secreted EVs.
- miR-146b mimics decreased embryo quality and blastocyst rates, while inhibitors improved quality.
- miR-146b regulated genes involved in apoptosis, cell differentiation, and transcription.
Conclusions:
- miR-146b is overexpressed in poor-quality bovine embryos and their EVs.
- miR-146b negatively regulates embryo development and promotes apoptosis.
- miR-146b is a potential biomarker and therapeutic target for improving embryo quality.
