Liénard Marjorie A, Lassance Jean-Marc X S, Paulmier Ivan, Picimbon Jean-François, Löfstedt Christer
Department of Ecology, Lund University, Sölvegatan 37, SE-223 62 Lund, Sweden.
J Insect Physiol. 2006 Jun;52(6):551-7. doi: 10.1016/j.jinsphys.2006.02.002. Epub 2006 Mar 20.
Social insects such as termites live in colonies in which cooperation is assumed by all individuals developing into castes to which specific tasks are allocated. Little has been reported about molecular aspects underlying termite caste-specific gene expression. Genetic regulation has recently been hypothesized to govern caste-specific traits and physiology in social insects. Cytochrome c oxidase (COX) has been shown to be an interesting candidate for expression study in insects. We used the cytochrome c oxidase subunit III gene (COXIII) that was cloned from mRNA in a lower termite, Reticulitermes santonensis De Feytaud (Isoptera; Rhinotermitidae). The full-length cDNA encodes a protein of 262 amino acids that shows high degree of homology with other insects COXIIIs. Reverse transcriptase-PCR and real-time PCR were performed to compare gene expression between larvae, workers, nymphs and soldiers. Analyses performed on head cDNAs revealed that COXIII is differentially expressed between castes. The level of COXIII is caste-regulated with an increase in workers (approximately 1.9-fold) and nymphs (approximately 2.8-fold) and a decrease in soldiers (0.8-fold) compared to the expression level in larvae (1.0-fold). These results may emphasize the physiological importance of COX in the termite brain at different developmental stages.
白蚁等群居昆虫生活在蚁群中，所有发育成不同等级的个体都有合作，每个等级都被分配了特定的任务。关于白蚁等级特异性基因表达的分子层面，此前报道甚少。最近有假说认为，基因调控决定了群居昆虫的等级特异性特征和生理机能。细胞色素c氧化酶（COX）已被证明是昆虫表达研究的一个有趣候选对象。我们使用从低等白蚁桑氏散白蚁（等翅目；鼻白蚁科）的mRNA中克隆得到的细胞色素c氧化酶亚基III基因（COXIII）。全长cDNA编码一种由262个氨基酸组成的蛋白质，该蛋白质与其他昆虫的COXIIIs具有高度同源性。进行逆转录聚合酶链反应（RT-PCR）和实时定量聚合酶链反应（real-time PCR）以比较幼虫、工蚁、若虫和兵蚁之间的基因表达。对头部cDNA进行的分析表明，COXIII在不同等级之间存在差异表达。与幼虫中的表达水平（1.0倍）相比，COXIII的水平受到等级调控，在工蚁中增加（约1.9倍），在若虫中增加（约2.8倍），在兵蚁中降低（0.8倍）。这些结果可能强调了COX在白蚁大脑不同发育阶段的生理重要性。
