Transcriptome-Guided Identification of Two GPCR Candidates Contributing to Trap Formation in Arthrobotrys oligospora

G protein-coupled receptors (GPCRs) connect environmental cues to fungal development, but the functions of many candidate receptors in nematode-trapping fungi remain unresolved. We combined reference-genome mining, public transcriptome analysis and functional assays to investigate GPCR candidates associated with trap formation in Arthrobotrys oligospora ATCC 24927. Genome mining yielded 87 candidate receptors, including two provisional entries. Transcriptome analysis across nine retained Gene Expression Omnibus (GEO) series supported an exploratory shortlist of three candidates, designated AoGrn1, AoGrn2 and AoGrn3. Deletion of AoGrn1 or AoGrn2 reduced nematode-induced trap formation, and complementation partially restored the phenotype. AoGrn3 deletion produced no statistically detectable change in trap density under the tested conditions. In HEK293F cells, nematode extract elicited bioluminescence resonance energy transfer responses in the AoGrn1–AoGpa2 and AoGrn2–AoGpa1 combinations. AlphaFold2-Multimer models suggested intracellular receptor–Gα interfaces, although model score preferences did not consistently match the observed response profiles. These findings support roles for AoGrn1 and AoGrn2 in trap formation and identify receptor–Gα combinations for further investigation of prey-associated signaling. The active extract components and the corresponding coupling relationships in the native fungus remain to be established.