Soldier presence suppresses presoldier differentiation through a rapid decrease of JH in the termite Reticulitermes speratus
Soldier presence suppresses presoldier differentiation through a rapid decrease of JH in the termite Reticulitermes speratus
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DOI：
10.1016/j.jinsphys.2011.03.005
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发表时间：
2011-06-01
影响因子：
2.2
通讯作者：
Maekawa, Kiyoto
中科院分区：
文献类型：
--
作者：
Watanabe, Dai;Gotoh, Hiroki;Maekawa, Kiyoto
种姓分化的调节是昆虫真社会性的基础。白蚁士兵是不育的，不能自己吃东西，因为它们有专门的嘴形态。几乎所有的白蚁物种都有一个士兵种姓，每个殖民地的士兵比例维持在一个较低的水平，可能是通过复杂的监管机制。虽然士兵的存在被认为是负面影响士兵分化在所有研究的物种，详细的机制仍不清楚。应用保幼激素（JH）可以人工诱导兵蚁分化，表明JH是兵蚁分化调控的关键因素。在这项研究中，阐明工人的生理变化，因为士兵的存在，在蜕皮到presolenum，JH III的应用程序和JH滴度定量进行了白蚁Reticulitermes speratus。首先，研究了JH III对工蜂诱导的换羽前士兵存在对换羽前的影响。有兵蚁的处理诱导的兵前蜕皮率显著低于无兵蚁的处理。其次，在JH施用后第0、5、10和15天，通过LC-MS定量在士兵存在或不存在下的工人JH滴度。结果表明，工人JH滴度（内源性+应用JH III）在士兵的存在下显着低于那些没有士兵在JH治疗后的第5天。在第10天和第15天，没有观察到这种士兵效应。最后，阐明了JH应用后士兵存在的有效持续时间。与士兵共存4天抑制了士兵前分化，表明士兵的存在迅速降低了其他集落成员中的JH滴度（即，工人），导致预焊接生产的抑制。(C)2011爱思唯尔有限公司保留所有权利。
The regulation of caste differentiation is essential to insect eusociality. Termite soldiers are sterile and cannot eat by themselves because they have specialized mouth morphology. Almost all termite species have a soldier caste, and the soldier ratio per colony is maintained at a low level, probably by elaborate regulatory mechanisms. Although the soldier presence is considered to negatively affect soldier differentiation in all examined species, the detailed mechanism remains unclear. Presoldier differentiation can be induced artificially by juvenile hormone (JH) application to workers, showing that JH is a key factor underlying the regulation of soldier differentiation. In this study, to elucidate physiological changes in workers because of the soldier presence during the molt into presoldiers, JH III applications and JH titer quantifications were carried out in the rhinotermitid termite Reticulitermes speratus. Firstly, the effects of soldier presence before the molt into presoldiers induced by JH III application to workers were investigated. The rates of presoldier molt induced by the treatments with soldiers were significantly lower than those without soldiers. Secondly, worker JH titers in the presence or absence of soldiers were quantified by LC-MS on day 0, 5, 10, and 15 after JH application. Results indicated that the worker JH titers (endogenous + applied JH III) in the presence of soldiers were significantly lower than those without soldiers on day 5 after the JH treatment. On days 10 and 15, such soldier effects were not observed. Finally, the effective duration of soldier presence after the JH application was elucidated. A 4 day period of co-existence with soldiers suppressed presoldier differentiation, suggesting that the soldier presence rapidly decreased the JH titer in other colony members (i.e., workers), resulting in the inhibition of presoldier production. (C) 2011 Elsevier Ltd. All rights reserved.