A simple method for producing tetraploid porcine parthenogenetic embryos

Area of Science:

• Reproductive Biology
• Developmental Biology
• Genetics

Background:

• Parthenogenesis is a mode of reproduction involving the activation of an egg without fertilization.
• Tetraploid embryos are crucial for certain biotechnological applications, such as somatic cell nuclear transfer.
• Efficient methods for producing tetraploid embryos are essential for advancing reproductive technologies in livestock.

Purpose of the Study:

• To develop a reliable method for producing porcine tetraploid parthenogenetic embryos.
• To investigate the developmental potential and chromosomal stability of these embryos.
• To utilize cytochalasin B to inhibit polar body extrusion and induce tetraploidy.

Main Methods:

• Porcine oocytes were matured and treated with cytochalasin B to prevent polar body extrusion, creating 0PB oocytes.
• 0PB oocytes were activated using electrical stimulation and further treated with cytochalasin B.
• Embryo development was assessed up to the blastocyst stage, with cell counts and FISH analysis performed.

Main Results:

• A high rate of oocytes (74.7%) treated with cytochalasin B failed to extrude a polar body (0PB).
• Nearly 50% of 0PB oocytes developed into blastocysts after activation and culture.
• FISH analysis confirmed the tetraploid nature of the embryos, with stable chromosome number maintenance.
• Tetraploid blastocysts had fewer cells compared to diploid controls.

Conclusions:

• Cytochalasin B treatment effectively produces porcine tetraploid parthenogenetic embryos.
• These tetraploid embryos can develop to the blastocyst stage and maintain their ploidy.
• The cell number in tetraploid blastocysts is lower than in diploid counterparts, indicating potential developmental differences.