Effects of Lycopene on Sheep Oocyte Maturation and Subsequent Parthenogenetic Embryo Development.

Area of Science:

• Reproductive Biology
• Biochemistry
• Developmental Biology

Background:

• Lycopene (LYC), a natural carotenoid, exhibits antioxidant and anti-apoptotic properties.
• LYC protects oocytes and embryos from reactive oxygen species (ROS) damage during in vitro culture.
• This protection can enhance in vitro maturation (IVM) and developmental competence of early embryos.

Purpose of the Study:

• To investigate the effects of varying lycopene concentrations (0, 5, 10, 15 μM) on sheep oocyte and early embryo development in vitro.
• To determine the optimal LYC concentration for improving developmental competence.

Main Methods:

• Sheep oocytes and early embryos were cultured in vitro with different LYC concentrations.
• Oocyte maturation rates, cumulus expansion, spindle assembly, and early embryonic development (cleavage, blastocyst formation) were assessed.
• Levels of ROS, glutathione (GSH), mitochondrial activity, mitochondrial membrane potential (MMP), and gene expression related to oxidative stress and apoptosis were measured.

Main Results:

• 5 μM LYC significantly increased the first polar body extrusion rate, cumulus expansion, and normal spindle assembly in oocytes.
• 15 μM LYC negatively impacted oocyte maturation.
• The 5 μM LYC group showed significantly higher cleavage and blastocyst rates, decreased ROS, elevated GSH, enhanced mitochondrial activity and MMP, and increased blastocyst cell numbers.
• LYC favorably regulated genes associated with oxidative stress and apoptosis in early embryos.

Conclusions:

• Lycopene supplementation, particularly at 5 μM, enhances sheep oocyte maturation and early embryonic development in vitro.
• LYC improves developmental competence by mitigating oxidative stress and improving mitochondrial function.
• These findings suggest LYC is a promising supplement for improving assisted reproductive technologies in sheep.