MATURATION AND SPAWNING OF WILD TIGER PUFFER TAKIFUGU RUBRIPES AND MECHANISM OF MATURATION ELUCIDATED BY CULTURED ONE

1995年，研究了用激素诱导养殖红鳍虎鲀卵巢成熟和排卵的有效方法，为水产养殖提供受精卵。LHRH-a胆固醇颗粒（LHRH-a 400 mg/kg）成功地诱导了3岁育成的卵黄蓄积卵巢的虎鲀过熟。单次注射HCG (500IU/kg)，联合大马哈鱼垂体（SP）匀浆（7mg /kg），实现鱼间同步排卵。在实验1（卵母细胞直径为900 mm的鱼）中，使用的7条鱼中有5条获得受精卵。在实验二（卵母细胞直径在800 - 900毫米之间的鱼）中，10条鱼中有8条获得受精卵。相反，在实验III中，采用常规方法（间隔5天重复注射HCG+SP，不处理LHRH-a）， 5条鱼中有2条获得受精卵。3个试验的平均受精率分别为55.1、53.6和11.0%。试验1和试验2中，排卵主要发生在注射HCG+SP后96 ~ 120小时。由此，开发了一种从养殖的老虎河豚中获得优质卵的技术。1996年：为获得老虎河豚（Takifugu ruberipes）真实催熟激素（MIH）的直接证据。为此，我们使用了处于卵母细胞发育四个不同阶段的无卵黄卵泡细胞。用^<14> c标记的17a-羟孕酮孵育卵泡细胞2小时，然后用层析分离放射性类固醇。所产生的放射性代谢物被鉴定并测试了它们在体外诱导卵母细胞生发囊泡破裂（GVBD）的能力。此外，通过监测最终卵母细胞成熟过程中的血清类固醇水平，研究了MIH候选物的体内生产。本研究结果证明20b-S是虎鲀体内天然存在的MIH。少

1995 : We developed the effective method of induction of ovarian maturation and ovulation of the cultured tiger puffer Takifugu rubripes by hormonal treatments in order to supply the fertilized eggs for aquaculture. The LHRH-a cholesterol pellet (LHRH-a 400 mg/kg) implantation successully induced overian maturation for three-year-old cultured tiger puffer which had yolk accumulated ovaries. Thereafter single injection of HCG (500IU/kg) combined with chum salmon pituitary (SP) homogenate (7 mg/kg) was applied to the fish to sinchronize ovulation among fish. In Experiment I (fish with oocytes *900 mm in diameter), fertilized eggs were obtained from 5 of 7 fish used. In Experiment II (fish with oocytes between 800 and 900 mm in diameter), fertilized eggs were obtained from 8 of 10 fish tereated. On the contrary, in Experiment III as a conventional method (repeated injection of HCG+SP at 5 days interval without LHRH-a treatment), fertilized eggs were obtained from two of 5 fish. Mean ferti … More lization rates in the three experiments were 55.1,53.6, and 11.0%, respectively. In Exp. I and II,ovulation was mainly occurred between 96 and 120 hours after HCG+SP injection. Thus, a thchnique for obtaining eggs of high quality from the cultured tiger puffer was developed.1996 : The study was designed to obtain derect evidence for the authentic maturation-inducing hormone (MIH) of tiger puffer, Takifugu ruberipes. To this end, we used yolk free follicle cells at four different stages of oocyte development. The yolk free follicle cells were incubated with the ^<14>C-labeled 17a-hydroxyprogesterone for 2hr, followed by chromatographic separation of the radioactive steroids. The radioactive metabolites produced were identified and tested for their ability to induce germinal vesicle breakdown (GVBD) in oocytes in vitro. Furthermore, in vivo production of candidates for MIH was investigated by monitoring the serum steroid levels during final oocyte maturation. The results obtained in this study provide evidence that 20b-S is the naturally occurring MIH in tiger puffer. Less