Cryopreservation of silkworm eggs

Abstract

To establish a method of long-term storage of silkworm eggs, the efficacy of cryopreservation was assessed by hanging culture of embryos after freezing treatment. Embryos of both diapause and non-diapause eggs failed to survive, when whole eggs were preserved at -30°C in a cryoprotection solution containing glycerol. Also no survivors were observed when dechorionated embryos were cryopreserved at -30°C; however, co-culture of these cryopreserved embryos with the extra-embryonic region of non-cryopreserved eggs resulted in partial development of embryos. Our finding suggests that the extra-embryonic region is much more sensitive for freezing than the embryo.