Chimerism in piglets developed from aggregated cloned embryos.

Area of Science:

• Developmental biology
• Stem cell research
• Animal models

Background:

• Porcine chimeras are crucial for studying pluripotency and developmental processes.
• Generating chimeric piglets from somatic cell nuclear transfer (SCNT) embryos is a significant goal.

Purpose of the Study:

• To produce live chimeric piglets by aggregating SCNT-derived embryos.
• To investigate the influence of donor cell characteristics on chimeric development.

Main Methods:

• Two donor cell lines expressing enhanced green fluorescent protein (EGFP) and tdTomato were used.
• SCNT embryos were reconstructed and aggregated at the 4-cell stage.
• Aggregated embryos were transferred to surrogate mothers, and resulting piglets were analyzed for chimerism.

Main Results:

• Live chimeric piglets were successfully produced and confirmed through various chimerism analyses.
• A notable bias towards EGFP-expressing cells was observed in the chimeric piglets.
• Hyper-methylation of the tdTomato gene promoter was suggested as a cause for reduced tdTomato expression.
• Altered expression of tumorigenicity-related genes was noted in bladder cancer cells post-tdTomato transfection.

Conclusions:

• Chimeric pigs can be generated by aggregating cloned embryos.
• Donor cell characteristics, such as promoter methylation, can impact the developmental potential of cloned embryos in chimeric development.