Effects on cell viability of three zebrafish testicular cell or tissue cryopreservation methods

In this work, three cryopreservation procedures were tested in order to obtain efficiently viable testicular cells after cryopreservation. Testicular cells of Wild type zebrafish males were frozen using an equilibrium protocol and testicular tissue fragments were cryopreserved with equilibrium freezing and vitrification procedures. Results showed that vitrification was significantly more efficient than freezing in terms of final cell survival (cell freezing: 14.4%, tissue freezing: 77.4%-85.5%, tissue vitrification: 94%). It must be noted that, in live cells, the presence of pseudopodia was frequently observed, which indicated their spermatogonial nature. Based on these results, the authors suggest that vitrification, with the subsequent elimination of connective tissue after warming, offers the best combination to rescue live testicular cells as a genetic conservation procedure in zebrafish.