Oocyte quality following in vitro follicle development(dagger)

In vitro follicle development (IVFD) is an adequate model to obtain basic knowledge of folliculogenesis and provides a tool for ovarian toxicity screening. IVFD yielding competent oocytes may also offer an option for fertility and species preservation. To promote follicle growth and oocyte maturation in vitro, various culture systems are utilized for IVFD in rodents, domestic animals, wild animals, nonhuman primates, and humans. Follicle culture conditions have been improved by optimizing gonadotropin levels, regulatory factors, nutrient supplements, oxygen concentration, and culture matrices. This review summarizes quality assessment of oocytes generated from in vitro-developed antral follicles from the preantral stage, including oocyte epigenetic and genetic profile, cytoplasmic and nuclear maturation, preimplantation embryonic development following in vitro fertilization, as well as pregnancy and live offspring after embryo transfer. The limitations of oocyte quality evaluation following IVFD and the gaps in our knowledge of IVFD to support proper oocyte development are also discussed. The information may advance our understanding of the requirements for IVFD, with a goal of producing competent oocytes with genetic integrity to sustain embryonic development resulting in healthy offspring. Summary Sentence Although advances in current IVFD systems have greatly enhanced oocyte growth and maturation, further optimization is required to improve oocyte competence with genetic integrity for proper embryonic development.

Automated summary

In vitro follicle development (IVFD) is a valuable model for understanding folliculogenesis, screening ovarian toxicity, and preserving fertility and species. This review discusses the culture systems used in IVFD across various species and the improvements made in follicle growth and oocyte maturation through optimization of culture conditions. The evaluation of oocyte quality following IVFD, including epigenetic and genetic profile, maturation, embryonic development, and pregnancy outcomes, is summarized. The review also highlights the limitations and knowledge gaps in IVFD for proper oocyte development. This information contributes to the goal of producing competent oocytes with genetic integrity for successful embryonic development and healthy offspring.