摘要Biology in the 21st century is shifting substantially towards single-cell analysis.Mammalian tissues are highly heterogeneous and contain multiple cell types in different states whose tight coordination determines overall function.Bulk measurements,including RNA sequencing,provide average values,which may dilute cell-specific effects or overlook rare effects of functional importance.This greatly limits our understanding of mammalian physiology and disease.For example,the histological structures of the cortical and medullary regions of the kidney differ substantially,and their cells exhibit distinct characteristics related to environmental gradients such as oxygenation,glomerular filtrate-induced shear stress,and solute concentrations within the nephron.