日本鰻早期人工誘導對卵巢發育影響之研究

Initial artificial induction on the influence of ovary development of Japanese eel (Anguilla japonica)

黃彥融(Yan-Rong Huang)

指導教授 ： 孫志陸

共同指導教授 ： 羅秀婉(Show-Wan Lou)

國立臺灣大學/理學院/海洋研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.02001

摘要

日本鰻 (Anguilla japonica) 在人工養殖下，性腺無法自然成熟，而停留在前卵黃生成期，需要利用外源性激素誘導的方式才能使其性腺更進一步發育，而為了了解日本鰻在人工誘導前後卵細胞發育之差異以及雄性素對其卵巢發育的影響，本實驗利用淡水養殖的上市日本鰻，體重在400~550公克的範圍內，經海水馴化一周後開始進行人工誘導。本實驗所使用的外源性激素分成單獨以鮭魚腦下垂體 (SPE) 以及SPE並用甲基睪固酮 (MT) 與11-酮基睪固酮 (11-KT) 的方式，每週進行一次人工誘導，分成一週及三週的處理組，並以JB-4樹脂切片，再利用卵細胞的形質做分期，來做出卵徑頻度分布，來觀察 (1) 人工誘導前後及 (2) 兩種雄性素對日本鰻卵巢形質特徵的影響。實驗結果發現，以SPE誘導後的日本鰻卵巢，相較於未人工誘導的日本鰻，GSI變大，細胞內油滴及表層胞數量明顯增加，而外層濾泡細胞也明顯增厚，大部分的卵細胞進入表層胞期，顯示人工誘導可促進日本鰻卵濾泡發育。而SPE並用兩種雄性素的結果，發現SPE+11-KT一週處理組，相較於SPE+MT一週處理組，油滴累積量較多，而SPE+11-KT三週處理組則與SPE+MT三週處理組就形質上無明顯差別。由以上的結果，發現人工誘導確實能讓卵細胞更進一步發育，而兩種雄性素的影響，以11-KT對於卵濾泡中的油滴累積影響較快速，而MT的影響則較緩慢，顯示出雄性素對日本鰻卵巢發育的重要性。

關鍵字

人工誘導 ； 雄性素 ； 卵濾泡分期 ； 前卵黃生成期 ； 組織切片

並列摘要

The Japanese eel (Anguilla japonica), cannot complete sexual maturation spontaneously under condition of cultivation, and stay in previtellogenic stage, therefore the methods for induction by exogenous sex hormone for gonad development is required. This experiment using freshwater cultivated Japanese eel, 400~550 g in bodyweight, acclimated in seawater in one week, before artificial induction .The exogenous hormones are divided into salmon pituitary extracts (SPE) alone, SPE with MT and SPE with 11- KT , weekly artificially induced, divided into one-week and three-week treatment group. We use JB-4 resin section, and using oocyte stage classification, to observe (1) before and after artificial induction and (2) two androgens effects on ovary characteristics of Japanese eel. The results found SPE induced Japanese eel ovarian follicles, compared to without artificially induction, oil droplets and cortical alveoli significantly increased in ooplasm, and thickening of the outer layer of follicle cells, most advanced oocytes enter the oil droplet stage, showing artificial induction can promote Japanese eel oocytes development. SPE and two androgens effect, in SPE+11-KT treatment group cumulative amount of oil droplets in ooplasm are more than SPE and SPE+MT treatment groups in one-week treatment , but in three week treatment groups, no significant differences are observed between two androgen groups. From the above results, suggest artificial induction can allow ovarian follicles further develop, and two androgen effects show11-KT effects on ovarian follicles in the cumulative of oil droplets are faster than MT effects, shows that androgen are important for ovarian development of Japanese eel.

並列關鍵字

artificial induction ； androgen ； Japanese eel ； previtellogenic ； JB-4 resin sections.

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