Elevated intracellular pH of zygotes during mouse aging causes mitochondrial dysfunction associated with poor embryo...

Area of Science:

• Reproductive Biology
• Developmental Biology
• Cellular Biology

Background:

• Maternal age is linked to increased preimplantation embryo mortality.
• The mechanisms behind age-related decline in embryo quality are not fully understood.

Purpose of the Study:

• To investigate the molecular mechanisms underlying poor embryo quality in aging mothers.
• To identify key molecular and cellular changes in zygotes due to maternal age.

Main Methods:

• Analysis of intracellular pH (pHi) in zygotes from young and aged mice.
• Measurement of mitochondrial membrane potential and reactive oxygen species (ROS) levels.
• Single-cell transcriptome sequencing of mouse zygotes to identify differentially expressed genes (DEGs).

Main Results:

• Aging significantly elevated pHi in zygotes, correlating with aberrant mitochondrial function and increased ROS.
• 120 genes showed significant differential expression between young and aged zygotes, including genes involved in cell division and ion transport.
• DEGs were enriched in pathways related to apoptosis, NF-kappa B signaling, and chemokine signaling, suggesting their role in regulating zygote quality.

Conclusions:

• Elevated zygote pHi due to maternal aging is a key factor contributing to poor embryo development.
• Transcriptomic analysis reveals specific genes and signaling pathways affected by aging that impact zygote quality and subsequent embryonic development.