Comparative transcriptomics and phylostratigraphy of Argentine ant odorant receptors

Nestmate recognition in ants is regulated through the detection of cuticular hydrocarbons by odorant receptors (ORs) in the antennae. These ORs are crucial for maintaining colony cohesion that allows invasive ant species to dominate colonized environments. In the invasive Argentine ant, Linepithema humile, ORs regulating nestmate recognition are thought to be present in a clade of nine exon odorant receptors, but the identity of the specific genes remains unknown. We sought to narrow down the list of candidate genes using transcriptomics and phylostratigraphy. Comparative transcriptomic analyses were conducted on the antennae, head, thorax, and legs of Argentine ant workers. We have identified a set of twenty-one nine-exon odorant receptors enriched in the antennae compared to the other tissues, allowing for downstream verification of whether they can detect Argentine ant cuticular hydrocarbons. Further investigation of these ORs could allow us to further understand the mechanisms underlying nestmate recognition and colony cohesion in ants.

蚂蚁的巢友识别通过触角中的气味受体（odorant receptors, ORs）检测表皮碳氢化合物来调控。这类气味受体对维持群体凝聚力至关重要，而这正是入侵性蚂蚁物种能够主导定植环境的关键因素。在入侵性阿根廷蚁（Linepithema humile）中，调控巢友识别的气味受体被认为隶属于一类具有9个外显子的气味受体进化支，但具体的基因身份仍未明确。本研究拟借助转录组学与系统地层学（phylostratigraphy）缩小候选基因的筛选范围。我们对阿根廷蚁工蚁的触角、头部、胸部及足开展了比较转录组分析，成功鉴定出21个相较于其他组织在触角中显著富集的9外显子气味受体，为后续验证其是否能够检测阿根廷蚁表皮碳氢化合物奠定了基础。对这些气味受体的进一步研究，将有助于我们深入解析蚂蚁巢友识别与群体凝聚力背后的分子机制。