Toga Kouhei, Hojo Masaru, Miura Toru, Maekawa Kiyoto
Graduate School of Science and Engineering, University of Toyama, Gofuku 3190, Toyama 930-8555, Japan.
Zoolog Sci. 2009 Jun;26(6):382-8. doi: 10.2108/zsj.26.382.
The ability of JHIII and three JHAs (hydroprene, pyriproxyfen and methoprene) to induce presoldier differentiation was tested in a highly derived termite, Nasutitermes takasagoensis (Isoptera: Nasutitermitinae), and induced presoldiers were examined morphologically and histologically. Hydroprene was the most effective hormone analog for the artificial induction of presoldier differentiation. Principal component analysis showed that hydroprene-induced presoldiers had similar external gross morphology to natural presoldiers found in the same colony. Induced presoldiers had a long, horn-like frontal projection, called a nasus, on the head. A well-developed reservoir and duct of the frontal gland were also observed inside the head. Scanning electron micrographs showed that the precursory structure forming the nasus (nasus disc) was developed under the cuticle of hydroprene-treated individuals just prior to the molt into presoldiers. Morphological changes in presoldier differentiation induced by hydroprene seemed to occur normally, compared with those in natural presoldiers. Thus, the present methods shown in this study will provide opportunities to conduct further molecular analyses on the molecular developmental bases of nasus formation during soldier differentiation in higher termites.
在一种高度特化的白蚁——高砂鼻白蚁（等翅目：鼻白蚁科）中，测试了保幼激素III（JHIII）和三种保幼激素类似物（烯虫酯、吡丙醚和甲氧普烯）诱导前兵蚁分化的能力，并对诱导产生的前兵蚁进行了形态学和组织学检查。烯虫酯是人工诱导前兵蚁分化最有效的激素类似物。主成分分析表明，烯虫酯诱导产生的前兵蚁与同一蚁群中自然产生的前兵蚁具有相似的外部总体形态。诱导产生的前兵蚁头部有一个长的、角状的额前突起，称为鼻。在头部内部还观察到额腺有一个发育良好的储液器和导管。扫描电子显微镜照片显示，在即将蜕皮成为前兵蚁时，烯虫酯处理个体的表皮下形成鼻的前体结构（鼻盘）开始发育。与自然前兵蚁相比，烯虫酯诱导的前兵蚁分化过程中的形态变化似乎正常发生。因此，本研究中所示的方法将为进一步开展关于高等白蚁兵蚁分化过程中鼻形成的分子发育基础的分子分析提供机会。
