Study on antennal transcriptome and olfactory receptor genes of Hemifusus tuba

Hemifusus tuba Gmelin is a marine gastropod species of significant economic importance, whose olfactory sensing mechanisms remain to be elucidated. The antennae of H.tuba were subjected to transcriptome sequencing using the Illumina HiSeq high-throughput sequencing platform. Bioinformatics analyses, including sequence assembly, functional annotation, database sequence retrieval, sequence alignment, and differential gene expression analysis, were performed to identify olfactory genes. The transcriptome sequencing generated 61 114 unigenes with an average length of 1 115 bp, an N50 of 1 599 bp, and a GC content of 42.9%. Through homology comparison, 10 olfactory receptor genes were identified and systematically named HetOR1–HetOR10. qRT-PCR analysis reveals tissue-specific expression patterns: HetOR2, HetOR3, HetOR7–HetOR10 exhibited relatively high expression levels in the antennae; HetOR1 was highly expressed in the gill; HetOR5 showed elevated expression in the foot; HetOR6 was predominantly expressed in the hepatopancrea; HetOR4 displayed high expression in both the antennae and mantle. The results suggest that the olfactory receptor genes in H. tuba might be involved in tissue-specific functional regulation, which provides fundamental data for understanding the molecular mechanisms of chemoreception in gastropods.