Paternal benzo[a]pyrene exposure affects gene expression in the early developing mouse embryo.

Area of Science:

• Reproductive toxicology
• Developmental biology
• Environmental health

Background:

• Paternal germ cell integrity is crucial for offspring health, with potential impacts from de novo mutations and epigenetic modifications.
• Polycyclic aromatic hydrocarbons, such as benzo[a]pyrene (B[a]P), are environmental contaminants with known carcinogenic, mutagenic, and reproductive effects.
• Understanding paternal exposure effects is vital due to the ubiquitous nature and reproductive toxicity of B[a]P.

Purpose of the Study:

• To investigate the effects of paternal exposure to benzo[a]pyrene (B[a]P) on early gene expression in mouse embryos.
• To assess how B[a]P exposure in male mice impacts the genetic material transmitted to offspring.
• To identify specific genes and developmental stages affected by paternal B[a]P exposure.

Main Methods:

• In vitro fertilization (IVF) using sperm from B[a]P-exposed male mice and oocytes from unexposed female mice.
• Acute B[a]P exposure (150 mg/kg) administered 4 days prior to sperm isolation.
• Gene expression analysis via reverse transcription-quantitative PCR (RT-qPCR) at multiple embryonic stages (zygote, 1-, 2-, 4-, 8-cell, and blastocyst).

Main Results:

• Paternal B[a]P exposure led to significant alterations in the expression of numerous genes in developing mouse embryos.
• The most pronounced gene expression changes were observed at the blastocyst stage.
• Some gene expression perturbations were also detected at earlier embryonic developmental stages.

Conclusions:

• Paternal exposure to the environmental contaminant B[a]P can disrupt embryonic gene expression.
• Embryonic gene expression profiling is a valuable tool for detecting disruptions in signaling pathways caused by contaminant exposure.
• This study provides insights into the mechanisms underlying paternal effects on early embryo development following environmental exposure.