Investigating Low-Temperature Stress Responses in Crustacea Aquatic Species Through Comparative Transcriptomics

Crustaceans, such as shrimp and crabs, are pivotal to global aquaculture, yet their productivity is severely impacted by low-temperature stress. This study employs comparative transcriptomic and genomic analyses to elucidate the molecular mechanisms underlying crustacean responses to cold stress across five economically significant species: <i>Litopenaeus vannamei</i>, <i>Penaeus indicus</i>, <i>Eriocheir sinensis</i>, <i>Cherax quadricarinatus</i>, and <i>Macrobrachium rosenbergii</i>. We identified 4711 conserved orthogroups and analyzed differential gene expression under low-temperature conditions. Results revealed species-specific responses, with 25 orthogroups shared across all five species and 113 orthogroups common to at least four species. Functional enrichment highlighted pathways such as oxidation-reduction, hormone metabolism, immune regulation, and spliceosomes. Key genes, including <i>EcKL</i>, <i>CYP2W1</i>, <i>HSPA5</i>, and <i>SLCs</i>, were implicated in signaling, metabolic, immunological, and developmental adaptations. Phylogenetic analysis was used to trace the evolutionary origins of stress-responsive genes, enabling the identification of both ancient conserved genes and lineage-specific genes. The results indicated that "younger" genes tend to exhibit greater transcriptional plasticity than ancient conserved genes. These findings provide critical insights into shared and species-specific low-temperature adaptation mechanisms, offering a foundation for breeding cold-tolerant crustacea strains to enhance aquaculture resilience.