Clock genes and environmental cues coordinate <i>Anopheles</i> pheromone synthesis, swarming, and mating

Abstract

<i>Anopheles</i> mating is initiated by the swarming of males at dusk followed by females flying into the swarm. Here, we show that mosquito swarming and mating are coordinately guided by clock genes, light, and temperature. Transcriptome analysis shows up-regulation of the clock genes <i>period</i> (<i>per</i>) and <i>timeless</i> (<i>tim</i>) in the head of field-caught swarming <i>Anopheles coluzzii</i> males. Knockdown of <i>per</i> and <i>tim</i> expression affects <i>Anopheles gambiae s.s.</i> and <i>Anopheles stephensi</i> male mating in the laboratory, and it reduces male <i>An. coluzzii</i> swarming and mating under semifield conditions. Light and temperature affect mosquito mating, possibly by modulating <i>per</i> and/or <i>tim</i> expression. Moreover, the desaturase gene <i>desat1</i> is up-regulated and rhythmically expressed in the heads of swarming males and regulates the production of cuticular hydrocarbons, including heptacosane, which stimulates mating activity.