Before seedlings can photosynthesize, they depend on fatty acids—and on peroxisomes to process them. Researchers discovered that the protein PEX11 not only helps these structures divide but also controls their size during early growth. When key genes were altered, peroxisomes grew abnormally large , suggesting internal vesicles normally keep them in balance. Remarkably, a yeast version of the protein fixed the problem, pointing to a deeply conserved mechanism across species. ...read more read less