Studies of the diversity and molecular evolution of defensive mechanism in termites

为了阐明白蚁防御系统的多样性和进化机制，本文以衍生最多的白蚁物种nasuttermes takasagoensis为研究对象，寻找与角状额突（nasus）发育和cembrene衍生多环二萜合成有关的基因。结果表明，一个同源盒基因远端缺失与鼻部发育有关。此外，利用下一代测序仪测定了所有与二萜前体有关的基因。尤其是香叶基二磷酸合成酶基因的重复扩增。这些结果表明，二萜的合成有助于在白蚁谱系中获得一种新的防御系统，以及适应性防御行为的获得。

To clarify the diversity and evolutional mechanisms of termite defensive system, I searched for the genes involved with the development of horn-like frontal projection (nasus) and the synthesis of cembrene-derived polycyclic diterpenes by using Nasutitermes takasagoensis which is the most derived termite species. The results indicated that a homeobox gene Distal-less is related to the development of the nasus. Moreover, all genes involved with the precursor of diterpene were determined using next generation sequencer. Especially, geranylgeranyl diphosphate synthase genes were duplicated repeatedly. These results suggest that the synthesis of diterpene is to contribute to the acquisition of a novel defensive system in a termite lineage, coupled with the acquisition of adaptive defensive behaviors.