Sagi A, Cohen D, Milner Y
Life Sciences Institute, Hebrew University of Jerusalem, Israel.
Gen Comp Endocrinol. 1990 Jan;77(1):15-22. doi: 10.1016/0016-6480(90)90201-v.
Mature males of the freshwater prawn, Macrobrachium rosenbergii (de Man), may change from one to another morphotype, according to a set sequence. Small males may develop into orange-claw males and orange-claw males into dominant blue-claw males. Each of the three morphotypes demonstrates distinctive reproductive behavior and secondary sexual characteristics. The role of the androgenic gland in this morphotypic transformation was examined experimentally by bilateral androgenic gland ablation (andrectomy) of small males and orange-claw males. For andrectomy initiated in the small male morphotype, transformation to the next morphotype was permitted (orange-claw), but subsequent transformation to the blue-claw morphotype was blocked. Andrectomy of orange-claw males did not prevent transformation into the blue-claw. Andrectomy on both small and orange-claw males caused disappearance of the genital papillae and atrophy of the sperm ducts and testes. The growth rates of the andrectomized small and orange-claw males were significantly lower than those of the unoperated and sham-operated controls. We conclude that androgenic gland factors control not only the differentiation of male secondary sexual characteristics but also morphotypic differentiation. Bioassays based on the results of this study will be instrumental in the characterization of such a factor(s).
罗氏沼虾（淡水虾）的成熟雄性个体可能会按照特定顺序从一种形态类型转变为另一种形态类型。小雄性个体可能发育成橙螯雄性个体，而橙螯雄性个体则发育成占主导地位的蓝螯雄性个体。这三种形态类型的每一种都表现出独特的生殖行为和第二性征。通过对小雄性个体和橙螯雄性个体进行双侧雄激素腺切除（去雄手术），对雄激素腺在这种形态类型转变中的作用进行了实验研究。对于从小雄性形态类型开始进行的去雄手术，允许其转变为下一种形态类型（橙螯），但随后向蓝螯形态类型的转变被阻断。对橙螯雄性个体进行去雄手术并不能阻止其转变为蓝螯形态。对小雄性个体和橙螯雄性个体进行去雄手术都会导致生殖乳头消失以及输精管和睾丸萎缩。接受去雄手术的小雄性个体和橙螯雄性个体的生长速度显著低于未手术和假手术对照组。我们得出结论，雄激素腺因子不仅控制雄性第二性征的分化，还控制形态类型的分化。基于本研究结果的生物测定将有助于鉴定此类因子。
