Delay in maternal transcript degradation in ovine embryos derived from low competence oocytes

Area of Science:

• Reproductive Biology
• Developmental Biology
• Molecular Biology

Background:

• Oocyte quality significantly impacts embryo development and offspring viability.
• Prepubertal oocytes exhibit lower developmental potential compared to adult oocytes.
• Understanding the molecular basis of this difference is crucial for improving reproductive outcomes.

Purpose of the Study:

• To compare the molecular profiles of oocytes and early embryos from adult and prepubertal sheep.
• To investigate gene expression patterns related to developmental competence.
• To identify molecular factors contributing to the reduced developmental potential of prepubertal oocytes.

Main Methods:

• Ovine model using oocytes from adult and prepubertal donors.
• Relative quantification of key genes (maternal effect, housekeeping, DNA methylation, imprinting, pluripotency, cell cycle).
• Temporal analysis during oocyte maturation and preimplantation embryo development.

Main Results:

• Prepubertal oocytes showed reduced transcript abundance compared to adult oocytes.
• Early embryos derived from prepubertal oocytes exhibited higher mRNA levels, indicating delayed maternal transcript degradation.
• Differential gene expression patterns were observed correlating with donor age and developmental competence.

Conclusions:

• Molecular differences in prepubertal oocytes contribute to their reduced developmental potential.
• Delayed maternal transcript degradation in early embryos is a novel finding associated with low-competence oocytes.
• This persistent transcript issue may impair early embryonic development and offers new insights into developmental competence.