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Bioscientific Studies on the Seaward and Spawning Migration of Salmonids in the North Pacific Oceans

北太平洋鲑鱼向海和产卵洄游的生物科学研究

基本信息

批准号：
63045001
负责人：
YAMADA Juro
金额：
$ 4.74万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for international Scientific Research
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

Captain Masuda (Oshoro-maru), professor Hatano (Hokkaido University), Associate Professor Yamauchi (Hokkaido University), Dr. Takagi (Hokkaido University) and Professor Mathisen (University of Alaska) obtained the fish samples in the Gulf of Alaska and the mouth, the middle and spawning ground of Copper River. After coming back to Japan, their analysis were performed. The results obtained are as follows : After1) Changes in circulating hormones during spawning migrationAt the start of chum salmon spawning migration, estradiol-17beta (E_2) levels raised, followed by the increase as spawning migration progressed. Vitellogenin contents also increased during the migration. However, the concentrations decreased on the spawning ground, whereas 17alpha, 20beta-dihydroxy-4-pregnen-3-one (DHP) increased dramatically. These results suggest that E_2 and DHP are involved in vitellogenesis and oocyte maturation, respectively.Thyroxine (T_4) and triiodothyronin (T_3) showed constant levels during sp … More awning migration. Interestingly, however, T_4 and T_3 were taken in the gonad at the start of the migration. These results indicate that T_4 and T_3 may be involved in the gonadal development.2) Changes in bone metabolismIn the sockeye salmon collected from Gulf of Alaska, both formation and resorption of the bone were very active. On the surface of the bone, there were very active osteoblasts forming bone matrix and mononuclear and multinuclear resorptive cells destroying and resorbing calcified matrix. These indicate rapid bone growth during the migration in the ocean. When the fish approached to the mouth of Copper River, activities of the bone formation and resorption decreased. At the spawning ground, on the other hand, almost no osteoblast and resorptive cells existed on the bone surface and bone growth stopped completely. No sexual difference was observed on the metabolism of bone.3) Changes in lipid synthesisIn accordance with the sexual maturation, chum salmon exhibited an obvious decrease in triglyceride synthetic activity in the liver tissue, while it was increased in the muscle tissue. This was attributed to homeostasis under extraordinary lack of lipid in the muscle tissue under the fasting condition during spawning migration without the substrate supply from the liver. The causes of the degenerative change such as the loss of lipid contents can be ultimately attributed to the progressed activation of lipid hydrolytic enzymes, since there was a remarkable increase in this activity in the liver tissue and also in the muscle tissues of male. Intactivation of lipid sysnthesis in the liver tissue is considered to give impetus to degenerative change.Professor Sven O. E. Ebbesson (University of Alaska) visited Hokkaido University, Japan, and exchanged the informations on salmon research with this project members. We made sure of keeping the further exchange of mutual informations. Less

增田船长（大雄丸）、波多野教授（北海道大学）、山内副教授（北海道大学）、高木博士（北海道大学）和Mathisen教授（阿拉斯加大学）在阿拉斯加湾和铜河河口、中部和产卵场获得了鱼类样本。回到日本后，他们进行了分析。1）产卵洄游过程中雌激素水平的变化在产卵洄游开始时，雌激素水平升高，随着产卵洄游的进行，雌激素水平逐渐升高。卵黄蛋白原含量也在迁移过程中增加。然而，产卵场的浓度下降，而17 α，20 β-二羟基-4-异戊烯-3-酮（DHP）急剧增加。上述结果表明，E_2和DHP分别参与卵黄发生和卵母细胞成熟过程，T_4和T_3在卵母细胞成熟过程中保持恒定水平 ...更多信息雨篷迁移。然而，有趣的是，T_4和T_3在迁移开始时就在性腺中被摄取。这些结果表明T_4和T_3可能参与性腺的发育。2）骨代谢的变化阿拉斯加湾红鲑骨的形成和吸收都很活跃。骨表面有活跃的成骨细胞形成骨基质，单核和多核吸收细胞破坏和吸收钙化基质。这表明在海洋中迁移期间骨骼生长迅速。当鱼接近铜河口时，骨形成和骨吸收活性降低。另一方面，在产卵场，骨表面几乎没有成骨细胞和吸收细胞存在，骨生长完全停止。骨骼代谢无性别差异。3）脂肪合成的变化随着性成熟，大麻哈鱼肝组织中甘油三酯合成活性明显降低，而肌肉组织中甘油三酯合成活性升高。这是由于在没有来自肝脏的底物供应的情况下，在产卵迁移期间禁食条件下肌肉组织中脂质异常缺乏的稳态。退行性变化的原因，如脂质含量的损失，最终可归因于脂质水解酶的活化，因为在雄性的肝脏组织和肌肉组织中，这种活性显著增加。肝组织中脂质合成的失活被认为是退行性变化的动力。E.美国阿拉斯加大学的Ebbesson教授访问了日本的北海道大学，并与项目成员交流了鲑鱼研究方面的信息。我们确保保持进一步的相互信息交流。少