TDO-mediated tissue-specific regulation of kynurenine pathway in the brain and gill of Litopenaeus vannamei

Our findings suggest that L. vannamei may compensate for IDO absence via tissue-specific TDO regulation, with brain-gill axis specialization reflecting adaptive metabolic plasticity. While structural divergences in LvTDO hint at evolutionary innovations, functional equivalence to vertebrate IDO/TDO systems requires further validation. This study highlights the evolutionary flexibility of KP in invertebrates, though metabolite dynamics and long-term physiological impacts remain to be explored.