Expression of miRNAs Associated With Embryo Development and DNA Damage Response in Porcine Embryos

Area of Science:

• Reproductive biology
• Epigenetics
• Developmental biology

Background:

• Embryo genome activation (EGA) and DNA Damage Response (DDR) are vital for embryonic development.
• Epigenetic mechanisms regulate both EGA and DDR.
• The role of microRNAs (miRNAs) in porcine embryo EGA and DDR is uncharacterized.

Purpose of the Study:

• To characterize miRNA expression in pig embryos during EGA.
• To investigate miRNA changes following DNA damage induction.
• To explore the link between miRNAs, EGA, and DDR in porcine embryos.

Main Methods:

• Assessed miRNA abundance across four developmental stages (D2, D3, D4, blastocyst).
• Induced DNA damage using UV exposure and validated with γH2AX immunofluorescence.
• Quantified mRNA levels of EGA-related genes to confirm developmental timepoints.

Main Results:

• Identified dynamic changes in specific miRNAs (miR-200a-5p, miR-15a, miR-24-3p) during porcine embryonic development.
• UV-induced DNA damage led to decreased blastocyst rates and cell numbers.
• DNA damage altered the expression of specific miRNAs (miR-29a-3p, miR-344b-3p) in blastocysts and affected miR-15a and miR-24-3p levels at D4.

Conclusions:

• This study provides the first characterization of miRNA expression during EGA in pig embryos.
• Specific miRNAs are implicated in the response to DNA damage in porcine embryos.
• Findings highlight the potential role of miRNAs in regulating porcine embryo development and DNA integrity.