Soluble trehalase affects the light sensitivity of Neocaridina denticulata sinensis by regulating eyestalk chitin...

Trehalase, primarily distributed in the digestive and circulatory systems of insects to hydrolyze trehalose into glucose, provides energy or serves as a precursor for macromolecule synthesis. In crustaceans, two isoforms of trehalases have been shown to enhance immunity by regulating apoptosis in gills. However, only the soluble trehalase gene (Tre1) was expressed and confirmed to function critically in the eyestalks. To clarify the functional differentiations, eyestalks from Neocaridina denticulata sinensis were subjected to transcriptome analysis after injection with dsNdTre1 for 12 h. The results showed the activation of phototransduction and chitin metabolism pathways, and 27 differentially expressed cuticle proteins (CPRs) genes were upregulated. Hole cracks in eyestalk cuticle were observed using the scanning electron microscope (SEM) after NdTre1 interference during the late premolt (D_2-4) stage. Abnormal photo-behaviors were triggered by eyestalk damage including increased light avoidance speed and higher shrimp density in dark places under short-wavelength blue light exposure, and the optimal light color for fishing was medium-wavelength green light. This study confirms the significance of trehalase in regulating chitin synthesis and CPRs and further provides evidence in maintaining the integrities of eyestalks to trigger normal swimming behaviors driven by light perceptions.