Cryopreservation of Grey Mullet Sperm

Abstract

中文摘要烏魚大規模繁殖技術已在台灣建立了 50 多年。本章係匯集烏魚精液冷凍保存之最適程序以期確保精液在繁殖需要時全年供應，在烏魚雜交育種的國際合作做出了貢獻。研究結果顯示，烏魚產卵季節在東港海岸附近洄游的雄性烏魚的性腺指數(GSI)為4到20的比例。每毫升生精液中約有 5.3 × 1010 個精子細胞；在溫度維持 5°C 的條件下仍能保持活力達23 天。在液氮中超低溫(-196°C)保存精子時需要結合冷凍保護劑。使用冷凍保護劑稀釋的新鮮精液分裝並密封到 0.5 毫升吸管中，以液氮蒸汽中預冷，直至溫度達到 -80°C。然後將它們放入液氮中進行長期保存。10% (DMSO) 的冷凍保護劑對精子樣品保存效果最佳。在這種情況下烏魚精液冷凍保護的實驗結果，冷凍前精子良好運動性和生育力。解凍冷凍烏魚精子的最佳結果是冷凍保存1年的精液具有中等活力和2.7%的生育能力。實作經驗，研究模式和技術成果有助於建構台灣烏魚精液保存和資料之重要參考。AbstractThe mass propagation techniques for grey mullet, one of the most important aquaculture species, has been established in Taiwan for more than 50 years. This chapter is a compilation of three previous studies undertaken to ensure the availability of mullet semen all year round whenever needed, which also contributed to international cooperation for cross breeding of grey mullet. Results showed that gonadosomatic index (GSI) of male grey mullet migrating near the coast of Tungkang ranged from 4 to 20 during the spawning season. There were about 5.3 × 1010 sperm cells per ml of raw semen with motility preserved for up to 23 d 5°C. Cryoprotective agents are needed in the preservation of sperm at ultra-low temperature (-196°C) in liquid nitrogen. Fresh semen diluted with cryoprotective agents dispensed and sealed into 0.5 ml straws are precooled in liquid nitrogen vapor until temperature -80°C is reached. They are then put into liquid nitrogen for long-term preservation. The cryoprotective agent with optimum effect on sperm preservation was 10% dimethyl sulfoxide (DMSO), which was found to have a synergistic effect in the recovery of cryopreserved samples. In this condition, both good motility and fertility before freezing as well as cryoprotection were obtained. The best result of thawed frozen mullet sperm was moderate motility and 2.7% fertility for semen cryopreserved for 1 year.