scRNA-seq reveals that nonimmune cell-type proportions are preserved with age. (A) Schematic representation of the experimental design. We isolated kidney, lung, and spleen tissue simultaneously from each young (7–8 mo) and old (22–23 mo) mouse. After generating single-cell suspensions, we prepared cells for scRNA-seq using the 10x Chromium system. (B) UMAP embeddings of each tissue investigated in our data set. Colors represent cell type annotations. Cell types were derived using a deep neural network classifier trained on the Tabula Muris data set, followed by manual validation using marker genes. (C) Matching UMAP embeddings depicting the age of each cell. (D) For each animal, we computed the proportion of cells in each cell identity. The mean proportion of each cell identity for each age across animals is presented as a bar graph. The underlying proportions observed in individual animals are overlaid as black dots. We observed an increased frequency of immune cell types in kidney and lung.
