Wilder M N, Okumura T, Aida K, Hanyu I
Department of Fisheries, Faculty of Agriculture, University of Tokyo, Japan.
Gen Comp Endocrinol. 1990 Oct;80(1):93-100. doi: 10.1016/0016-6480(90)90152-c.
Ecdysteroid levels during the embryogenesis of the giant freshwater prawn, Macrobrachium rosenbergii, were determined by radioimmunoassay and high-performance liquid chromatography. Ecdysteroids consisting of significant amounts of 20-hydroxyecdysone and high-polarity products (HPP) and lesser amounts of ecdysone and low-polarity products (LPP) were detected in mature ovaries and newly laid eggs. All ecdysteroid groups decreased gradually during the nauplius phase. With the formation of the compound eye and the appearance of the carapace and other body-like structures, marking morphogenesis to the zoeal stage, embryos showed the beginning of a continuous and dramatic increase in ecdysteroid concentrations sustained until larval hatchout. Ecdysteroid levels at hatchout were above 20-fold greater than ecdysteroid levels in newly laid eggs. More specifically, HPP and 20-hydroxyecdysone increased concomitantly, with a decrease in 20-hydroxyecdysone only at the end of the embryogenic period, while ecdysone and LPP levels remained low or undetectable. It may be postulated that the presence of ecdysteroids in ovaries and eggs represents a reserve of maternal ecdysteroids which are necessary at the commencement of embryonic development; with the differentiation of embryonic tissue capable of ecdysteroid synthesis, ecdysteroids increase rapidly to play a role in later embryonic development.
采用放射免疫分析法和高效液相色谱法测定了罗氏沼虾胚胎发育过程中的蜕皮甾类激素水平。在成熟卵巢和新产出的卵中检测到了蜕皮甾类激素，其中20-羟基蜕皮酮和高极性产物（HPP）含量较高，蜕皮酮和低极性产物（LPP）含量较低。在无节幼体阶段，所有蜕皮甾类激素组的含量均逐渐下降。随着复眼的形成以及头胸甲和其他类似身体结构的出现，标志着胚胎发育进入蚤状幼体阶段，此时胚胎的蜕皮甾类激素浓度开始持续急剧增加，直至幼体孵化。孵化时的蜕皮甾类激素水平比新产出卵中的蜕皮甾类激素水平高出20倍以上。更具体地说，HPP和20-羟基蜕皮酮同时增加，仅在胚胎发育末期20-羟基蜕皮酮含量有所下降，而蜕皮酮和LPP水平则一直较低或无法检测到。可以推测，卵巢和卵中蜕皮甾类激素的存在代表了母体蜕皮甾类激素的储备，这在胚胎发育开始时是必需的；随着能够合成蜕皮甾类激素的胚胎组织的分化，蜕皮甾类激素迅速增加，在后期胚胎发育中发挥作用。
