The tissue regeneration of sea cucumber (Apostichopus japonicus) involves precise intercellular signal pathway transduction and gene expression regulation. This study investigated the function of the Notch signaling pathway in A. japonicus papilla regeneration and its modulation by LED light of varying intensities. We detected the expression patterns of Notch signaling pathway-related genes and their downstream cell proliferation-related genes during papilla regeneration, and further verified the pathway function via gene silencing, combined with histological analyses to explore LED-mediated effects. Gene expression assays revealed that AjNotch, AjSu(H), AjHes1, AjCyclinA, AjCyclinD and AjCDK8 were significantly upregulated at 28 days post papilla excision (p < 0.05). LED light treatment accelerated papilla regeneration in a light intensity-dependent manner, with the most pronounced promotion at 2000 lx (p < 0.05). Moreover, LED light treatment was associated with altered expression of Notch signaling pathway genes and their downstream proliferation-related genes in a light intensity-dependent manner. Gene silencing of AjNotch significantly downregulated its downstream target genes (p < 0.05), attenuated the regenerative promotion of LED light, and reduced cell proliferation rate (p < 0.05). These findings suggest that the Notch signaling pathway is pivotal for A. japonicus papilla regeneration, and LED light modulates papilla regeneration with concurrent changes in the expression of Notch pathway-related genes. This study provides novel insights into the function of the Notch signaling pathway in echinoderm regenerative development.
Cui et al. (Mon,) studied this question.