Efficient generation of bone morphogenetic protein 15-edited Yorkshire pigs using CRISPR/Cas9†

Area of Science:

• Reproductive Biology
• Developmental Biology
• Genetics

Background:

• Bone morphogenetic protein 15 (BMP15) is vital for ovarian follicular development in species with single ovulation.
• Previous research suggested BMP15 has a limited role in female fertility and ovarian development in polyovulatory species.
• However, BMP15 knockdown in pigs significantly impaired fertility and caused ovarian abnormalities, implying a critical role in polyovulatory species.

Purpose of the Study:

• To investigate the regulatory role of BMP15 in porcine ovarian and follicular development.
• To generate BMP15-edited pigs using CRISPR/Cas9 technology.

Main Methods:

• CRISPR/Cas9 gene editing was used to create BMP15-edited Yorkshire pigs.
• Artificial insemination experiments were conducted to assess the fertility of edited gilts.
• Ovarian morphology and follicular development were analyzed in infertile gilts.

Main Results:

• Biallelically edited BMP15 gilts were infertile, irrespective of genotype.
• One monoallelically edited gilt (Δ66 bp/WT) was fertile and produced offspring comparable to wild-type gilts.
• Infertility in biallelically edited gilts resulted from arrested follicular development, abnormal follicle formation, streaky ovaries, and absent estrous cycles.

Conclusions:

• BMP15 plays a significant role in regulating female fertility and ovarian follicular development in polyovulatory species like pigs.
• The function of BMP15 in nonrodent polyovulatory species appears as critical as in mono-ovulatory species.
• BMP15 gene editing provides a model for studying its role in reproductive processes.