Oxidative homeostasis and survival instincts of chicken egg, embryo and adult

Chicken embryos and stem cells require precisely regulated levels of reactive oxygen species (ROS) to maintain self-renewal and pluripotency. However, excessive ROS induces oxidative stress, leading to DNA damage, chromosomal aberrations, loss of mitochondrial membrane potential, and ultimately, abnormal differentiation or cell death. This oxidative imbalance is a significant barrier to successful embryonic development and the in vitro culture of stem cells. Innate antioxidant defense systems exist within chicken and mammalian embryos to scavenge excess ROS, a finding that has prompted the strategic addition of antioxidants to culture media. The present review has two primary foci. Firstly, it seeks to expand the understanding of the antioxidant defense mechanisms of the chicken embryo. Secondly, it explores the role of exogenous antioxidant supplementation in the culture of various stem cell types, including embryonic stem cells (ESCs), primordial germ cells (PGCs), spermatogonial stem cells (SSCs), and induced pluripotent stem cells (iPSCs). Enhancing in vitro stem cell survival and directed differentiation through antioxidant supplementation holds significant promise for advancing fields such as tissue regeneration, organ transplantation, and the development of transgenic chicken models for improved production traits, vaccine development, and recombinant protein production.