Full length transcriptome sequencing of salivary glands of Pteromalus puparum

Here, using integrative full-length transcript sequencing and expression profiling, we generated an isoform-resolved transcriptomic landscape of salivary genes in the endoparasitoid wasp Pteromalus puparum. We identified 133 high-confidence salivary genes, more than 75% of which produced multiple transcript isoforms.

Proteomic analyses confirmed that alternative splicing directly contributes to salivary protein diversity, with eight genes encoding distinct protein isoforms. Twelve salivary genes exhibited gland-biased isoform usage, including PpSerpin3, whose short isoform was specifically expressed in salivary and venom glands and suppressed host melanization. Comparative multi-omics analyses further revealed that salivary and venom systems share a conserved genetic core but achieve functional specialization through tissue-specific gene family co-option and extensive isoform switching.