# Transcriptomic Analysis of Venom Secretion in Achelura yunnanensis: Lipid Metabolism, Redox Reactions, and Structural Adaptations

## TL;DR

This study explores how Achelura yunnanensis larvae produce venom by comparing gene activity in venom-producing and non-venom tissues, revealing key metabolic and structural adaptations.

## Contribution

The study identifies lipid metabolism, redox reactions, and structural adaptations as critical for venom secretion in Achelura yunnanensis larvae.

## Key findings

- Venom-producing tissue shows upregulated lipid metabolism and redox pathways, crucial for venom stabilization and secretion.
- LDET downregulates genes related to epidermal development, reallocating resources to venom production.
- Lipid metabolism genes make up 18.3% of differentially expressed genes, indicating their central role in venom secretion.

## Abstract

Venom in insects, like the larvae of Achelura yunnanensis, helps them defend against predators, but how they produce and release this venom is not fully understood. In this study, we explored the differences between two parts of the larvae: the dorsal epidermis tissue, which makes venom, and the larval proleg tissue, which does not. We looked at the activity of thousands of genes in these tissues to understand what makes the venom-producing tissue special. Our findings show that the venom tissue relies heavily on processes that create fats, manage chemical reactions, and build protective layers on its surface. These processes help the tissue store and release venom safely while protecting itself from harm. This work reveals the complex ways insects prepare their defenses, which could help us develop new methods to control pest insects that harm crops or spread diseases. By understanding how insects like these larvae protect themselves, we can find better ways to manage them in agriculture and improve safety for farmers and the environment.

As a key pest damaging urban greenery in Yunnan, China, Achelura yunnanensis larvae secrete venom for defense, yet the molecular basis of this process remains poorly understood. This study aimed to uncover the molecular mechanisms of venom secretion by comparing the dorsal epidermis tissue (LDET) with the larval proleg tissue (LP). We performed transcriptomic analysis using RNA sequencing to identify differentially expressed genes between LDET and LP (10 biological replicates per tissue type), followed by functional enrichment and gene expression correlation analyses to explore tissue-specific characteristics. LDET exhibited significant upregulation of pathways related to lipid metabolism, redox reactions, and surface protective structure formation, suggesting their roles in venom stabilization, activation, and safe secretion. Conversely, genes linked to non-venom-related functions, such as extracellular matrix organization and epidermal development, were downregulated in LDET, indicating resource reallocation toward venom production. These findings reveal a multi-component mechanism in LDET that supports venom secretion through metabolic and structural adaptations, with lipid metabolism genes constituting 18.3% of total differentially expressed genes, highlighting evolutionary trade-offs in insect defense. This study provides new insights into insect venom secretion and offers potential targets for pest control strategies.