A critical requirement for a systems-level understanding of complex biological processes such as aging is the ability to directly characterize interactions between cells and tissues within a multicellular organism. C. elegans nematodes harboring mutations in the insulinlike receptor daf-2 exhibit dramatically-increased lifespans. To identify tissue-specific biochemical mechanisms regulating aging plasticity, we single-cell sequenced 3'-mRNA libraries generated from seven populations of whole day-one adult wild-type and daf-2 -/-