Hartfelder Klaus, Köstlin Konstanze, Hepperle Christine
Zoologisches Institut, LS Entwicklungsphysiologic, Auf der Morgenstelle 28, D-72076, Tübingen, Germany.
Rouxs Arch Dev Biol. 1995 Sep;205(1-2):73-80. doi: 10.1007/BF00188845.
In the honey bee, Apis mellifera, the fifth larval instar is a critical period for caste differentiation. During this premetamorphic phase the hormonal milieu shows pronounced caste differences and several organs, particularly the ovaries, enter different developmental pathways leading to highly fertile queens and nearly sterile workers. Developmental profiles of total protein synthesis in larval ovaries showed marked caste differences starting with the early fifth instar. By two-dimensional electrophoresis, caste-specific patterns could be detected in the synthesis of a 29 kDa/pI 4.6 and two 24 kDa/pI 5.2-5.5. proteins (pI=isoelectric point). A marked decrease in the expression of these proteins was found to coincide with caste-specific differences in the haemolymph ecdysteroid titer. In vitro exposure of larval worker ovaries to physiological (10 M) concentrations of synthetic makisterone A elicited an identical response. Juvenile hormone did not affect protein synthesis patterns in larval ovaries, and also did not inhibit or reverse the ecdysteroid-induced effects. Heat shock experiments revealed that the 29 kDa/pI 4.6 ecdysteroid-regulated protein belongs to the class of small heat shock proteins.
在蜜蜂（西方蜜蜂）中，幼虫的第五龄期是 caste 分化的关键时期。在这个前变态阶段，激素环境呈现出明显的 caste 差异，并且几个器官，特别是卵巢，进入不同的发育途径，导致高度可育的蜂王和几乎不育的工蜂。幼虫卵巢中总蛋白质合成的发育概况显示，从五龄初期开始就存在明显的 caste 差异。通过二维电泳，可以在 29 kDa/pI 4.6 和两种 24 kDa/pI 5.2 - 5.5 的蛋白质（pI = 等电点）的合成中检测到 caste 特异性模式。发现这些蛋白质表达的显著下降与血淋巴蜕皮甾类滴度的 caste 特异性差异相一致。将幼虫工蜂卵巢在体外暴露于生理浓度（10 M）的合成 makisterone A 会引发相同的反应。保幼激素不会影响幼虫卵巢中的蛋白质合成模式，也不会抑制或逆转蜕皮甾类诱导的效应。热休克实验表明，29 kDa/pI 4.6 的蜕皮甾类调节蛋白属于小热休克蛋白类别。
