The Role of Glucose Metabolism in Xenopus Primitive Myeloid Cell Development and Function

Primitive Myeloid Cells (PMCs) arise from the anterior ventral blood islands during Xenopus laevis embryogenesis and migrate to colonize embryonic tissues, contributing to wound healing, innate immunity, and development. Because cell movement and growth are metabolically demanding, we investigated whether metabolic pathways regulate PMC behaviour integrating public single-cell RNA-seq data with whole-mount in situ hybridization (WMISH) to profile metabolic gene expression in PMCs, followed by functional assays using pathway-specific inhibitors: 2-deoxy-D-glucose 2-DG (global glucose metabolism), YZ-9 (glycolysis), 6-AN (pentose phosphate pathway, PPP), and ST045849 (hexosamine biosynthetic pathway, HBP). The analyses showed that PMCs express high levels of glycolytic and ancillary metabolic enzymes. Global inhibition impaired PMC colonization and wound recruitment and modestly reduced the size of the specification domain, confirming a requirement for glycolytic flux. PPP and downstream glycolysis inhibition produced only modest, non-significant shifts in recruitment, whereas HBP inhibition abolished wound recruitment and reduced PMC numbers. These findings identify glucose metabolism as a regulator of PMC colonization and immune function, revealing how metabolic reprogramming governs early immune cell behaviour independent of a functional vasculature.