Fig. 1: Major cell types identified in developing Drosophila lymph glands.

a A schematic diagram of the Drosophila lymph gland (left). Prohemocytes comprise the medullary zone at the inner core (blue) and give rise to mature hemocyte at the outermost area, called the cortical zone (red). Differentiating hemocytes in between the medullary zone and the cortical zone are termed the intermediate zone (yellow). The posterior signaling center (PSC) positions at the posterior end of the lymph gland (pink). Drosophila lymph glands (blue, DAPI) at three timepoints (72, 96, and 120 h AEL; After Egg Laying) (middle). Schematic workflow of sample preparation for scRNA-seq using Drop-seq (right). Scale bar, 30 μm. Lymph glands are demarcated by white dotted lines. b DAPI-positive cell counts of a single lymph gland lobe (n = 30 each for three timepoints). Red horizontal lines show median counts (397, 1392, and 4557 for 72, 96, and 120 h AEL, respectively). c A t-SNE plot showing the two-dimensional projection of eight major cell types identified in the scRNA-seq dataset (n = 22,645 in total; 72 h AEL, 2321; 96 h AEL, 9400; 120 h AEL, 10,924 cells). The count of each cell type is indicated in parentheses. Clusters are defined by following markers: Prohemocytes (PH: Tep4, Ance; 36.2%), Plasmatocytes (PM: Hml, Pxn, NimC1; 57.6%), Crystal cells (CC: lz, PPO1, PPO2; 1.3%), Lamellocytes (LM: atilla; 1.5%), the PSC (Antp, col; 0.9%), and Dorsal Vessel (DV: Mlc, Hand; 0.1%). Colors denote cell types. Dotted lines demarcate prohemocytes (blue) and plasmatocytes (red). d Two-dimensional projections of major cell types along developmental timepoints (left) and proportion of the cell types at each timepoint (right). Proportions of prohemocytes (blue) and plasmatocytes (red) are indicated. e Relative proportion (indicated as proportional ratio; top) and normalized cell counts (bottom) of each major cell type. Colors represent sampling timepoints.