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.

蚂蚁的巢友识别过程，通过触角内的嗅觉受体（odorant receptors, ORs）识别表皮碳氢化合物来实现调控。此类嗅觉受体对于维持群体凝聚力至关重要，而群体凝聚力正是入侵蚁种得以在定殖环境中占据主导地位的核心因素。就入侵物种阿根廷蚁（Linepithema humile）而言，调控巢友识别的嗅觉受体被认为存在于一个由九外显子嗅觉受体构成的进化支中，但具体基因的身份仍未明确。本研究旨在通过转录组学与系统发育谱系地层学（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，最终鉴定出21个相较于其他组织在触角中显著富集的九外显子嗅觉受体，为下游验证这些受体是否可识别阿根廷蚁表皮碳氢化合物奠定了基础。对这些嗅觉受体的深入研究，将助力我们进一步解析蚂蚁巢友识别与群体凝聚力的潜在分子机制。