Alternative Splicing Dynamics Associated with Nutritional Transition and Starvation-Induced PNR in Leiocassis...

Alternative splicing (AS) increases transcriptomic diversity; however, its role in teleost larval nutritional physiology remains undetermined. This study investigated alternative splicing (AS) dynamics associated with nutritional transition and the starvation-induced point of no return (PNR) in Leiocassis longirostris larvae. Using RNA sequencing and rMATS across eight developmental phases, differentially spliced events (DSEs) and differentially spliced genes (DSGs) were identified between the feeding and starvation trajectories. A total of 84,172 AS events were found, with 93.4% of which were skipped exons (SE). DSEs accumulated in a stage-dependent manner during feeding but increased suddenly under starvation, reaching peak levels at the PNR. DSGs were enriched in cell adhesion, energy sensing, and metabolic reprogramming pathways, with SE splicing most strongly correlated with the progression of starvation. The integration of DSGs with differential exon usage (DEU) revealed 47 PNR-core genes, including zak, lama2, mbpa, and nhsl2, which were validated by RT-PCR analysis. The results showed that AS dynamics are associated with stage-dependent regulatory coordination of developmental adaptation and starvation-induced PNR in L. longirostris larvae. This study identified molecular targets that may improve larval survival in aquaculture.