Cell Lineage-Guided Microanalytical Mass Spectrometry Reveals Increased Energy Metabolism and Reactive Oxygen Species in the Vertebrate Organizer

The vertebrate body plan is established through inductive signaling during gastrulation via a signaling center, which is called the Spemann-Mangold organizer (SMO) in the developmental model Xenopus laevis, the South African Clawed Frog. Here, we performed a multiplexed quantitative proteomic screen of the SMO in contrast with the rest of the embryo (RE). Wild-type embryos were cultured to the 32-cell stage, where precursor cells of the SMO were injected with a fluorescent lineage tracing dye. These experimental embryos were cultured to stage 10 (beginning of gastrulation), whence the fluorescently labelled cells were dissected. The proteome of the SMO and the RE were quantified using multiplexing quantification. The tissue samples were processed using a bottom-up proteomic workflow and analyzed using LC-MS3. The resulting data revealed an upregulation of oxidative phosphorylation (OXPHOS) in the SMO tissues.