Tissue-Specific Detection of Autophagy and the Related Metabolites in Bombyx mori.

Tissue-specific autophagic remodeling drives larval tissue dismantling during lepidopteran metamorphosis, yet the metabolic regulators underlying tissue-autonomous autophagic heterogeneity remain incompletely defined. This study sought to dissect the linkage between lipid metabolic reprogramming and tissue-divergent autophagic potency in Bombyx mori. Spatiotemporal autophagic levels across larval tissues was profiled via BmAtg8-PE immunoblotting, BmAtg8 immunofluorescence, and LysoTracker Red lysosomal staining. Untargeted metabolomics was conducted on the fat body, midgut, posterior silk gland, and trachea at key metamorphic stages; differentially accumulated metabolites (DAMs) were processed through hierarchical clustering and KEGG functional enrichment. Autophagic activity was universally upregulated upon prepupal transition, with the posterior silk gland and trachea showing markedly higher autophagic levels, whereas the fat body and midgut maintained relatively lower autophagic activity in tissue-wide comparison. Lipids represented the most dynamically remodeled metabolite families; fatty acyls and their synthetic cascades were enriched in high-autophagy tissues, while glycerolipid and glycerophospholipid pathways prevailed in low-autophagy tissues. Integrative multi-omics and cytological evidence identify a correlative relationship between tissue-resolved lipid turnover and spatially segregated autophagic activation. This tissue-scale atlas establishes a fundamental resource for mechanistic exploration of lipid-autophagy crosstalk governing insect metamorphic development.