Figure 4.

CF depletion induces proliferation of phagocytes. Sea urchins (n = 6) were injected with EdU and 5% of the estimated BV was depleted by CF aspiration. CF was collected from each animal on days 0–6, and phagocytes were processed for immunofluorescence to determine phagocyte type based on size, cytoskeletal morphology, SpTrf expression, and EdU incorporation. The resulting dataset of differential cell counts of 1,000 cells/sample/animal/day was used for the analyses that are displayed in both panels. (A) The EdU⁻ phagocyte types show minor variations in the proportions of each cell type over time. Discoidal cells are present at higher levels than polygonal cells and both are present at higher levels than the other phagocyte types. The EdU⁺ phagocytes show increases in all types of phagocytes, with the most notable increases in the polygonal, medium, and small phagocytes. (B) EdU incorporation for each phagocyte type is shown as the fraction of the total number of cells of each type. Both medium and small phagocyte populations show elevated EdU incorporation.