Culture systems: embryo co-culture

Area of Science:

• Reproductive Biotechnology
• Developmental Biology
• Cell Culture Technology

Background:

• Embryonic developmental arrest in vitro, particularly during maternal to zygotic transition (MZT), challenged early animal biotechnology.
• Blastocyst formation is critical for successful embryo transfer in farm animals to prevent expulsion.

Purpose of the Study:

• To review the historical development and application of coculture strategies in overcoming embryonic developmental arrest.
• To highlight the role of feeder cells in supporting blastocyst development in both animal and human assisted reproductive technologies (ART).

Main Methods:

• Early coculture strategies utilized trophoblastic tissue, followed by oviduct and uterine epithelial cells.
• Established cell lines, including African Green Monkey Kidney (Vero) cells, were developed for their embryotrophic properties.
• Coculture with buffalo rat liver (BRL) or Vero cells is employed for precious embryos in animal biotechnology.

Main Results:

• Coculture significantly improved blastocyst development compared to classical media, mimicking in vivo conditions.
• Feeder cells, particularly Vero cells, provide essential embryotrophic support through the release of growth factors and free radical scavengers.
• Coculture with autologous uterine cells yields superior results in human ART compared to sequential media.

Conclusions:

• Coculture technology has been pivotal in advancing both animal and human reproductive biotechnology by enabling successful blastocyst development.
• The use of specific cell lines and autologous cells continues to be a valuable strategy in ART for enhancing embryo viability.