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Updated: Jul 6, 2026
Loss- and Gain-of-function Approach to Investigate Early Cell Fate Determinants in Preimplantation Mouse Embryos
Published on: June 6, 2016
MicroRNA expression in preimplantation mouse embryos from Ped gene positive compared to Ped gene negative mice
Michael J Byrne1, Carol M Warner
1Biology Department, Northeastern University, 134 Mugar Hall, 360 Huntington Avenue, Boston, MA, 02115, USA.
Purpose:
The mouse preimplantation embryo development (Ped) gene product, Qa-2, influences the rate of preimplantation embryonic development and overall reproductive success. Here we investigated the expression pattern of two microRNAs, miR-125a and miR-125b, known to be involved in development in lower organisms, in preimplantation embryos from the two-cell, four-cell, eight-cell, morula, and blastocyst stages of development from the congenic B6.K1 (Ped negative) and B6.K2 (Ped positive) strains of mice.
Method:
B6.K1 and B6.K2 congenic mice differ only in the absence (B6.K1) or presence (B6.K2) of the genes encoding Qa-2 protein. We analyzed the expression of miR-125a and miR-125b in B6.K1 and B6.K2 preimplantation embryos by using real-time PCR.
Result:
We found no variability in miR-125b expression at any developmental stage in both strains. However, miR-125a expression increased during development in both strains and was ten times higher in Ped negative (B6.K1) embryos than in Ped positive (B6.K2) embryos by the blastocyst stage of development.
Conclusion:
Our results show that the absence of the Ped gene profoundly affects the level of a miRNA (miR-125a) known to regulate early development. The implication is that miR-125a is likely involved in the regulation of timing of early development in mice.
Insights
The absence of the preimplantation embryonic development (Ped) gene significantly impacts miR-125a levels in mouse embryos. This suggests miR-125a plays a key role in regulating early embryonic development timing.
Area of Science:
- Developmental Biology
- Genetics
- Reproductive Science
Background:
- The preimplantation embryonic development (Ped) gene product, Qa-2, influences embryonic development rate and reproductive success in mice.
- MicroRNAs (miRNAs) are small non-coding RNAs involved in gene regulation and development.
Purpose of the Study:
- To investigate the expression patterns of miR-125a and miR-125b in mouse preimplantation embryos.
- To determine the effect of the Ped gene on miRNA expression during early development.
Main Methods:
- Congenic mouse strains B6.K1 (Ped negative) and B6.K2 (Ped positive) were used.
- Preimplantation embryos were collected at various developmental stages (two-cell, four-cell, eight-cell, morula, blastocyst).
- Real-time PCR was employed to analyze miR-125a and miR-125b expression levels.
Main Results:
- miR-125b expression showed no variability between strains or developmental stages.
- miR-125a expression increased throughout development in both strains.
- Ped-negative (B6.K1) embryos exhibited ten times higher miR-125a expression than Ped-positive (B6.K2) embryos at the blastocyst stage.
Conclusions:
- The absence of the Ped gene significantly alters miR-125a levels in early mouse embryos.
- miR-125a is implicated in the regulation of the timing of preimplantation embryonic development in mice.
