Abstract: 【Aim】To identify cytochrome P450 (CYP450) genes and their full-length transcripts in the larval guts of Apsi cerana cerana workers using nanopore sequencing technology and offer reference information and basis for further functional study.【Methods】The 4-6-day-old larval gut transcriptomes of A. cerana cerana workers were sequenced by Nanopore PromethION platform. Quality control of raw reads was performed using Guppy software to gain clean reads. Full-length transcript sequences were detected through recognizing primers at both ends. The sequences of the above-mentioned full-length transcripts were aligned to the Nr and GO databases with BLAST tool to identify CYP450 genes and their full-length transcripts. Astalavista software was used to identify alternative splicing (AS) events of genes. RT-PCR was used to validate the reliability of AS events of various types. 【Results】In the 4-6-day-old larval guts of A. cerana cerana workers, 7 338 627, 7 003 419 and 7 434 233 raw reads were obtained, respectively, and after quality control, 7 289 494, 6 959 880 and 7 387 756 clean reads were gained. The total number of identified non-redundant fulllength transcripts was 48 200. Forty-seven CYP450 genes and their 265 full-length transcripts were identified. A total of 90 AS events of CYP450 genes were identified, including 36 exon skipping events, 20 alternative 5′ splicing site events, 17 intron retention events, nine alternative 3′ splicing site events and eight mutually exclusive exon events. The RT-PCR result confirmed the authenticity of randomly selected three types of AS events. 【Conclusion】 The findings provide CYP450 genes and their full-length transcripts in A. cerana cerana, supplement the annotation of A. cerana reference genome, and reveal that CYP450 genes of A. cerana cerana can generate abundant isoforms via multiple AS types.

Key words: Apis cerana cerana, larvae, third-generation sequencing technique, cytochrome P450, full-length transcripts, alternative splicing