The neuronal A-to-I RNA editome of Solenopsis invicta expands conserved recoding repertoire between two ant species

BACKGROUND: A-to-I RNA editing expands proteomic diversity and may contribute to caste-specific phenotypic plasticity in eusocial insects. However, the quantity-accuracy trade-off in editing detection usually hinders comprehensive characterization of the RNA editome. MATERIALS AND METHODS: To overcome the quantity-accuracy trade-off, we first perform de novo identification of the neuronal A-to-I editome of the red imported fire ant Solenopsis invicta, and then apply an orthology-based strategy to project candidate editing sites to another ant species Acromyrmex echinatior. RESULTS: We obtain nearly 3000 editing sites in S. invicta, including 91 nonsynonymous (recoding) sites enriched in neuronal functions such as synaptic transmission, ion channels, and circadian rhythms. The orthology-based strategy substantially expands the previously known recoding repertoire in the leaf-cutting ant A. echinatior, reveals many previously missed recoding sites and edited genes, and uncovers additional caste-specific recoding events between gynes and workers, highlighting conserved, potentially functional editing targets across ant evolution. Representative recoding sites are validated by Sanger sequencing. CONCLUSION: Our work expands ant RNA editome resources and identifies conserved recoding candidates that may facilitate future studies of eusocial caste diversification, neuronal function, and phenotypic plasticity.