Artificial gynogenesis was successfully induced in the Pacific oyster using ultraviolet (UV)-irradiated sperm. Inactivation of sperm chromosomes was achieved when sperm were irradiated for 5-6 min at a UV (253.7 nm) intensity of 1080 μW/cm2. Fertilization of eggs with genetically inactivated sperm produced primarily haploid development which terminated before reaching D-stage. Cytochalasin B (CB) treatment applied during meiosis II blocked the release of the second polar body in 83% of the gynogenetically activated eggs. Following diploidization, 18% of the activated eggs survived to D-stage. Although the post-D-stage survival was low, viable gynogenetic diploids were obtained. CB treatment applied to block both polar body I and II produced high levels of gynogenetic tetraploids (95%) which were not detected at 2 months post-fertilization. The use of inbred females did not improve the survival of gynogenetic animals in this study. The low survival of the gynogenetic animals was probably caused by genetic damage resulting from UV irradiation of sperm.
All Science Journal Classification (ASJC) codes
- Aquatic Science