Parsing the Pancreas

High-resolution analysis of gene expression in individual pancreatic cells is providing new insights into cell subpopulations and candidate genes relevant to the causes and progression of pancreatic disorders. The identity of any given cell is determined by its transcriptome — that is, the set of genes that are actively transcribed into RNA in that cell. A disease condition or the elements of the cell environment, such as hormones, paracrine factors, and nutrients, can also determine the functional state of the cell, in a process that often involves changes in the transcriptome. Traditional analyses of bulk populations of cells, even when they are highly purified by cell sorting with cell type–specific markers, represent a mean of the population and may hide cellular heterogeneity — for example, the presence of . . .