Hymenopteran ‐specific TRPA channel from the Texas leaf cutter ant (Atta texana) is heat and cold activated and expression correlates with environmental temperature

Texas leaf cutter ant (Atta texana) populations have expanded northward and their obligate symbiotic fungus has increased cold tolerance. The ants have exquisitely temperature sensitive antennae; here, we find the antennae express a subset of six transient receptor potential (TRP) channels, including HsTRPA. When expressedin vitro, HsTRPA shows activation by both heat and cooling temperature stimuli, withQ10 values>100 on initial activation. The channel shows minimal activity between 20 and 33 °C, which coincides well with behavioral tests showing the ants prefer 24 °C for fungal growth. AbstractLeaf cutting ants of the genusAtta cultivate fungal gardens, carefully modifying environmental conditions to maintain optimal temperature for fungal growth. Antennal nerves fromAtta are highly temperature sensitive, but the underlying molecular sensor is unknown. Here, we utilizeAtta texana (Texas leaf cutter ant) to investigate the molecular basis of ant temperature sensation and how it might have evolved as the range expanded northeast across Texas from ancestral populations in Mexico. We focus on transient receptor potential (TRP) channel genes, the best characterized temperature sensor proteins in animals.Atta texana antennae express 6 of 13 Hymenopteran TRP channel genes and sequences are under a mix of relaxed and intensified selection. In a behavioral assay, we findA. texana workers prefer 24 °C (range 21−26 °C) for fungal growth. There was no evidence of regulatory ev...
Source: Insect Science - Category: Biology Authors: Tags: ORIGINAL ARTICLE Source Type: research