# Transcriptome Analysis of Potential Genes Involved in Innate Immunity in Mudflat Crab (Helice tientsinensis)

## TL;DR

This study explores how mudflat crabs respond to Vibrio infection by analyzing gene expression changes in their gills and hepatopancreas.

## Contribution

The study identifies differentially expressed genes and immune pathways in mudflat crabs during Vibrio infection, offering new insights into crustacean immunity.

## Key findings

- Vibrio parahaemolyticus infection causes structural damage in gill and hepatopancreatic tissues of H. tientsinensis.
- Transcriptome analysis identified thousands of differentially expressed genes linked to ribosomal subunits and energy transport.
- Key immune pathways and amino acid metabolism are involved in the crab's defense against Vibrio infection.

## Abstract

Vibrio species are widely recognized as highly pathogenic bacteria in aquaculture, causing extensive mortality among cultured organisms and resulting in substantial economic losses. H. tientsinensis, a dominant crustacean species in the Yellow River Delta, has been the subject of limited investigation regarding its susceptibility to Vibrio infection. In this study, we examined structural alterations and differential gene expression in the gill and hepatopancreatic tissues of H. tientsinensis following infection with Vibrio parahaemolyticus, and further explored the associated metabolic and immune responses. The findings provide valuable insights into the defense mechanisms of crustaceans against Vibrio pathogens and offer a scientific foundation for aquaculture management and targeted disease prevention strategies.

The mudflat crab (H. tientsinensis) is a dominant species in coastal tidal flat areas, primarily inhabiting the high tide region of the intertidal zone, and possesses significant ecological and economic value. Vibrio species are one of the main bacterial pathogens responsible for diseases in marine organisms, and they are widely distributed in seawater and estuarine environments. However, the immune mechanisms employed by H. tientsinensis in response to Vibrio infections remain unclear. This study aims to investigate the physiological and immune mechanisms by analyzing the structural changes and differential gene expression in the gill and hepatopancreas following Vibrio parahaemolyticus infection. The results indicate that V. parahaemolyticus infection causes cellular damage, with structural alterations observed in the gills (epithelial cell edema in the gill filaments, and aneurysm formation) and the hepatopancreas (changes in lumen size, nuclear condensation, and modifications in connective tissue morphology). Transcriptome analysis revealed 9766 differentially expressed genes (DEGs) in the gills of the experimental group, with 4687 upregulated and 5079 downregulated genes. These DEGs are primarily involved in different ribosomal subunits. In the hepatopancreas, 1594 DEGs were identified, with 834 upregulated and 760 downregulated. These DEGs are predominantly associated with energy-coupled proton transmembrane transport, electron transport-coupled proton transport, and lipid transporter activity. H. tientsinensis gene annotation and KEGG enrichment analysis revealed that chemical carcinogens DNA adducts, amino acid metabolism, and some immune pathways play key roles in the ability of H. tientsinensis to defend against V. parahaemolyticus infection. The findings of this study contribute to a deeper understanding of the immune mechanisms of H. tientsinensis against V. parahaemolyticus infection and provide new insights for aquaculture management.