Sexual difference in juvenile-hormone titer in workers leads to sex-biased soldier differentiation in termites.
Sexual difference in juvenile-hormone titer in workers leads to sex-biased soldier differentiation in termites.
复制标题
工蚁保幼激素滴度的性别差异导致了白蚁中性别偏向的士兵分化。
DOI：
10.1016/j.jinsphys.2016.02.005
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发表时间：
2016
期刊：
影响因子：
2.2
通讯作者：
Maekawa K
中科院分区：
文献类型：
--
作者：
Toga K;Hanmoto S;Suzuki R;Watanabe D;Miura T;Maekawa K
在白蚁中，士兵阶层以其特殊的防御形态，是其最重要的社会性特征之一。大多数基蚁种都有雄性和雌性士兵，士兵的性别比例几乎相等或仅略有偏差。然而，在顶端谱系（特别是白蚁科）中，有许多物种的士兵具有强烈的性别比例偏差。一般来说，在白蚁中，由于高幼体激素（JH）滴度是工蚁从工蚁分化到工蚁前阶段所必需的，因此有假设认为，雄性和雌性工蚁在JH敏感性和/或JH滴度上的差异导致了士兵性别比例的偏倚。因此，我们重点研究了自然条件下只有雄性士兵的Nasutitermes takasagoensis和同时有雄性和雌性士兵的Reticulitermes speratus的兵前分化和工蜂JH滴度。在前一个物种中，有四种类型的工蜂；男小工、男中工、女中工和女大工，以及士兵与男小工的区别。首先，我们试图从男性和女性工人中人工诱导士兵。客栈。高agoensis，在雄性小工蜂中分化率和死亡率显著高于其他工蜂。形态学分析表明，男性和女性诱导的前士兵都具有正常的士兵特异性形态。这表明女工在自然条件下与士兵没有区别，但也保持了士兵分化的生理和发育潜力。印度卢比。然而，在焊料分化率和死亡率方面，男女工人没有差异。其次，采用高效液相色谱-质谱联用技术，在不同季节（4月和12月）对不同性别/类型工人的JH滴度进行定量分析。结果表明，inN。男性未成年工种的高agoensis， JH滴度始终高于其他工种。印度卢比。相比之下，男性和女性工人的JH滴度无显著差异。这些结果表明，inN。高agoensis，雄性小工虫在一年中保持较高的JH滴度，这可能导致雄性偏向的前工虫分化。
In termites, the soldier caste, with its specialized defensive morphology, is one of the most important characteristics for sociality. Most of the basal termite species have both male and female soldiers, and the soldier sex ratio is almost equal or only slightly biased. However, in the apical lineages (especially family Termitidae), there are many species that have soldiers with strongly biased sex ratio. Generally in termites, since high juvenile hormone (JH) titer is required for soldier differentiation from a worker via a presoldier stage, it was hypothesized that the biased soldier-sex ratio was caused by differences in JH sensitivity and/or JH titer between male and female workers. Therefore, we focused on the presoldier differentiation and the worker JH titer in species with only male soldiers (Nasutitermes takasagoensis) and with both male and female soldiers (Reticulitermes speratus) in natural conditions. In the former species, there are four types of workers; male minor, male medium, female medium and female major workers, and presoldiers differentiate from male minor workers. First, we tried to artificially induce presoldiers from male and female workers. InN. takasagoensis, the presoldier differentiation rate and mortality was significantly higher in male minor workers. Morphological analyses showed that both male and female induced presoldiers possessed normal soldier-specific morphologies. It was suggested that female workers, from which soldiers do not differentiate under natural conditions, also maintained the physiological and developmental potential for soldier differentiation. InR. speratus, however, no differences were observed in solder differentiation rate and mortality between male and female workers. Second, the JH titers of each sex/type of workers were quantified by high performance liquid chromatography–mass spectrometry in two different seasons (April and December). The results showed that, inN. takasagoensis, JH titer in male minor workers was consistently higher than those in other worker types. InR. speratus, in contrast, there were no significant differences in JH titers between male and female workers. These results suggested that, inN. takasagoensis, male minor workers maintain JH titers at a high level throughout a year, and this may cause the male-biased presoldier differentiation.