OSMOREGULATORY MECHANISMS DURING EARLY LIFE STAGES IN FISH AND THEIR HORMONAL CONTROL

鱼类生命早期阶段的渗透调节机制及其激素控制

• 批准号: 06405004
• 负责人: HIRANO Tetsuya
• 金额: $ 10.69万
• 依托单位: UNIVERSITY OF TOKYO
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (A)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-06405004/
• 关键词: Euryhaline fish; Embryos and larvae; Early development; Osmoregulation; Hormones; Cortisol; Prolactin; Chloride cells

The aim of this study is to clarify osmoregulatory mechanisms during early life stages of euryhaline fishes, specifically in euryhaline tilapia (Oreochromis mossambicus), and their hormonal control. The results obtained during the last 2 years are as follows.1. Prolactin cells identified by immunocytochemistry and in situ hybridization were developed earlier in the tilapia embryos developed in fresh water (FW) than those in seawater (SW), suggesting its important role in FW adaptation as in adult fish.2. Chloride cells on the yolk-sac membrane of tilapia embryos and larvae reared in FW developed earlier than in those in SW,and cortisol, SW-adapting hormone in the adult fish, accelerated their development.3. Tilapia larvae started drinking seawater 2 days after hatching. Drinking rate, as measured by accumulation of ^<14>C-dextran in the gut, was still greater in the larvae in SW than those in FW,and the drinkig rate increased as the larvae grow.4. Turnover rate of tritiated water in tilapia embryos and larvae in FW were twice as great as those in SW,whereas the turnover rate of ^<36>Cl was 50-80 folds greater in SW than in FW.5. Field studies indicated the importance of thyroid hormones and cortisol in the development of digestive system during early embryonic stages and also during metamorphosis from larval to juvenile stages in several marine species such as flounders, tunas and seabreams.

本研究的目的是阐明广盐性鱼类，特别是广盐性罗非鱼（Oreochromis mossambicus）的早期生命阶段的激素调节机制及其激素控制。在过去两年中取得的成果如下。通过免疫细胞化学和原位杂交鉴定，在淡水环境中发育的罗非鱼胚胎中，催乳素细胞的发育早于海水环境中发育的胚胎，提示其在淡水适应中的重要作用与成鱼相同.淡水条件下罗非鱼胚胎和仔鱼卵黄囊膜上氯细胞的发育早于海水条件下，而成鱼体内的海水适应激素--皮质醇对胚胎和仔鱼的发育有促进作用.罗非鱼仔鱼在孵化后2天开始饮用海水。饮水率（以<14>消化道中的β-葡聚糖积累量来衡量）在SW中的幼虫仍大于FW中的幼虫，且饮水率随幼虫的生长而增加.氚水在罗非鱼胚胎和仔鱼中的周转率，FW是SW的2倍，而氯离子的周转<36>率SW是FW的50-80倍.实地研究表明，甲状腺激素和皮质醇在比目鱼、金枪鱼和海鸟等几种海洋物种的早期胚胎阶段以及从幼虫到幼鱼阶段的变态过程中对消化系统发育的重要性。

项目成果

Kaneko,T.et al.: "Hypoosmoregulatory ability of eyed-stage embryos of chum salmon." Marine Biology. 122. 165-170 (1995)

Kaneko,T.et al.：“鲑鱼有眼阶段胚胎的低渗透压调节能力。”

Tagawa,M.et al.: "Thyroid hormone concentrations in the gonads of wild chum salmon during maturation." Fish Physiology and Biochemistry. 13. 233-240 (1994)

Takawa,M.et al.：“野生鲑鱼成熟过程中性腺中的甲状腺激素浓度。”

Ayson,F.G.et al.: "Development of mitochondrion-rich cells in the yorl-sac membrane of embryos and larvae of tilapia in freshwater and seawater." Journal Experimental Zoology. 270. 129-135 (1994)

Ayson，F.G.等人：“淡水和海水中罗非鱼胚胎和幼虫的卵囊膜中富含线粒体的细胞的发育。”

Kinoshita, I., S.Fujita, I.Takahashi, K.Azuma, T.Noichi, and M.Tanaka: "A morphological and meristic comparison of larval and juvenile temperate bass, Lateolabrax japonicus, from various sites in western and central Japan." Japan.J.Ichthyol.42. 165-171 (1

Kinoshita, I.、S.Fujita、I.Takahashi、K.Azuma、T.Noichi 和 M.Tanaka：“来自日本西部和中部不同地点的温带鲈鱼 (Lateolabrax japonicus) 幼鱼和幼鱼的形态和分枝比较

Kaneko,T.er al.: "Hypoosmoregulatory ability of eyed stage embryos of chum salmon,Oncorhynchus keta" Marine Biology. (印刷中).

Kaneko, T.er al.：“鲑鱼 Oncorhynchus keta 有眼阶段胚胎的低渗透压调节能力”海洋生物学（正在出版）。