The researchers developed a method to freeze and store spermatogonia (sperm precursor cells) from striped catfish testes. They found that spermatogonia can survive freezing without needing extra substances in the freezing solution. The frozen cells showed signs of cell death, but some key genes related to sperm production were still active. When transplanted into fish larvae, the frozen cells were able to grow and develop, showing that they can still function after being frozen. This study shows that spermatogonia from striped catfish can be successfully preserved through freezing, keeping their important characteristics intact.