Tissue levels of deoxynucleotide triphosphates (dNTPs) are tightly regulated, and their dysregulation can impair DNA replication, leading to DNA damage and genetic instability. dNTPs can be synthesized de novo in a cell-autonomous pathway, imported from the extracellular environment, or recycled intracellularly through the salvage pathway. Whether nucleotides can be directly exchanged between neighbouring cells in vivo remains unknown. Boumard, Le Meur et al. present evidence for direct intercellular transfer of nucleotides in certain adult tissues of Drosophila melanogaster.

Closer examination of the minority of double-mutant clones showing DNA damage revealed that only cells located far from any wild-type neighbouring cells were affected. This finding led the authors to hypothesize that a mechanism based on nucleotide transfer from neighbouring wild-type cells may compensate for the loss of cell-intrinsic nucleotide replenishment mechanisms.