Institute for Zoology, University of Regensburg, Universitätsstraße 31, D-93040, Regensburg, Germany.
Hungarian Department of Biology and Ecology, Babeș-Bolyai University, Clinicilor 5-7, 400006, Cluj-Napoca, Romania.
Commun Biol. 2023 Feb 16;6(1):183. doi: 10.1038/s42003-023-04541-7.
Many parasites interfere with the behaviour of their hosts. In social animals, such as ants, parasitic interference can cause changes on the level of the individual and also on the level of the society. The ant-parasitic fungus Rickia wasmannii influences the behaviour of Myrmica ants by expanding the host's nestmate recognition template, thereby increasing the chance of the colony accepting infected non-nestmates. Infected ants consistently show an increase of the alkane tricosane (n-C23) in their cuticular hydrocarbon profiles. Although experimental application of single compounds often elicits aggression towards manipulated ants, we hypothesized that the increase of n-C23 might underlie the facilitated acceptance of infected non-nestmates. To test this, we mimicked fungal infection in M. scabrinodis by applying synthetic n-C23 to fresh ant corpses and observed the reaction of infected and uninfected workers to control and manipulated corpses. Infected ants appeared to be more peaceful towards infected but not uninfected non-nestmates. Adding n-C23 to uninfected corpses resulted in reduced aggression in uninfected ants. This supports the hypothesis that n-C23 acts as a 'pacifying' signal. Our study indicates that parasitic interference with the nestmate discrimination of host ants might eventually change colony structure by increasing genetic heterogeneity in infected colonies.
许多寄生虫会干扰宿主的行为。在社会性动物中，如蚂蚁，寄生虫的干扰会导致个体和社会层面的变化。寄生真菌 Rickia wasmannii 通过扩展宿主的同种识别模板来影响蚂蚁的行为，从而增加了群体接受感染的非同种个体的机会。受感染的蚂蚁在其表皮碳氢化合物谱中始终表现出烷二十三烷（n-C23）的增加。虽然单个化合物的实验应用通常会引发对受操作蚂蚁的攻击，但我们假设 n-C23 的增加可能是感染的非同种个体更容易被接受的基础。为了验证这一点，我们通过向新鲜蚂蚁尸体上施加合成的 n-C23 来模拟真菌感染，观察感染和未感染工蚁对对照和操作尸体的反应。感染的蚂蚁对感染但未感染的非同种个体似乎更为平静。向未感染的尸体中添加 n-C23 会导致未感染的蚂蚁的攻击性降低。这支持了 n-C23 作为“安抚”信号的假设。我们的研究表明，寄生真菌对宿主蚂蚁同种识别的干扰可能会通过增加感染群体的遗传异质性最终改变群体结构。
