Exploring the potential of prepubertal oocytes: a small ruminant model

Area of Science:

• Reproductive biology
• Developmental biology
• Animal science

Background:

• Juvenile in vitro embryo transfer (JIVET) utilizes oocytes from prepubertal females to shorten generation intervals.
• This technique has potential applications in human fertility preservation for young cancer patients.
• Ruminant animals serve as valuable models due to similarities in follicular dynamics and oocyte competence with humans.

Purpose of the Study:

• To review biomarkers of oocyte competence in relation to follicle size (≤3 mm vs. >3 mm) in prepubertal females.
• To analyze in vitro maturation (IVM) strategies for improving oocyte developmental potential.
• To determine factors influencing successful JIVET outcomes.

Main Methods:

• Analysis of existing literature on oocyte competence and follicle size.
• Comparison of biomarker levels (e.g., fatty acids, EGF receptor expression) in different follicle sizes.
• Evaluation of IVM strategies including CAPA-IVM, BMP15 supplementation, and antioxidant addition.

Main Results:

• Prepubertal oocytes exhibit lower n-3 fatty acid levels and higher cumulus cell EGF receptor expression in larger follicles (>3 mm).
• Condensed germinal vesicle (GV) configuration is similar in adult and prepubertal large follicles.
• Prepubertal oocytes are more susceptible to oxidative stress compared to adult oocytes.

Conclusions:

• Oocyte competence for JIVET is primarily linked to the follicular state rather than female age.
• Optimizing in vitro maturation (IVM) conditions and selecting appropriate follicles are crucial for enhancing JIVET success.
• Further research into follicular selection and IVM protocols can improve outcomes for fertility preservation and breeding programs.