Brain and antennal transcriptomes of host ants reveal potential links between behaviour and the functioning of socially parasitic colonies

Social ant parasites are characterised by exploiting the social behaviour of their hosts. Why exactly hosts direct their altruistic behaviour towards these parasites and their offspring remains largely unstudied. One hypothesis is that hosts do not perceive their social environment as altered and accept the parasitic colony as their own. We used the ant Leptothorax acervorum, host of the dulotic, obligate social parasite Harpagoxenus sublaevis to shed light on molecular mechanisms underlying behavioural exploitation by contrasting tissue-specific gene expression in young host ants. Therefore, host pupae were experimentally (re-)introduced into parasitic colonies, their natal, or another conspecific colony. After the emerged host workers were about 10 weeks old, we recorded their behaviour and then sampled them for sequencing of antennal and brain gene expression to analyse genes affected by the social environment the ants lived in as well as those genes that correlate with the behaviours performed the hour before sampling.

社会性蚂蚁寄生虫以其利用宿主社会行为为特征。究其原因，为何宿主会将其利他行为指向这些寄生虫及其后代，这一问题至今研究甚少。一种假说认为，宿主并未感知其社会环境发生改变，并接纳寄生群体为其自身。本研究采用蚂蚁Leptothorax acervorum，该蚂蚁为宿主，而其寄生者为专性社会寄生虫Harpagoxenus sublaevis，旨在揭示行为利用背后的分子机制。通过对比年轻宿主蚂蚁组织特异性基因表达，我们引入宿主幼虫至寄生群体、原生态群体或另一同种群体进行实验。待宿主工蚁大约10周龄时，记录其行为并采集样本，进行触角和大脑基因表达的测序，以分析受蚂蚁所处社会环境影响及与采样前一小时行为相关的基因。