Fish ES cells and applications to biotechnology

Area of Science:

• Animal Biotechnology
• Developmental Biology
• Genetics

Background:

• Embryonic stem (ES) cells are vital for generating transgenic animals with targeted mutations.
• Current ES cell technology is primarily limited to mice, with significant interest in extending it to fish species.
• Transgenic fish are valuable for functional genomics and enhancing commercial productivity.

Purpose of the Study:

• To describe the procedure for developing fish ES cells.
• To address key challenges in maintaining pluripotency and germline competence in fish ES cells.
• To evaluate the potential of ES cell technology for genetic modification in fish.

Main Methods:

• Focus on two model fish species: zebrafish and medaka.
• Key techniques involve preventing cell differentiation and identifying in vitro pluripotency markers.
• Crucially, assessing chimeric animal production to confirm ES cell pluripotency and germline transmission.

Main Results:

• Detailed step-by-step protocols for fish ES cell development are presented.
• Challenges in achieving long-term germline competence with fish ES cells were identified.
• Demonstrated the potential for generating chimeric fish, indicating successful pluripotency.

Conclusions:

• Establishing functional fish ES cells is challenging but achievable, with zebrafish and medaka as key models.
• Alternative strategies like primordial germ cells and nuclear transfer may be necessary due to germline competence issues.
• Despite slow progress, advancements in homologous recombination offer promising avenues for future fish ES cell technology.