Fig 1: Quantification and localization of identified immune cell populations among epididymal regions (scale bar 20 µm).(A) Distribution (assessed by flow cytometry n=4-8, bar diagram showing mean ± SD) of total leukocytes (CD45+ cells) and localization within the initial segment and corpus, as shown by immunostaining of CD45. (B–H) Quantification and localization of the following immune cell populations were assessed by flow cytometry and immunostaining using selected markers (n=4–8, mean ± SD). The following markers were used: CD45, F4/80, CD11B, Ly6C, MHC-II, CLEC9A, CD209A, CD163, CCR2, CX3CR1 for identifying myeloid cell populations, and CD45, B220/CD45R, CD3, TCRß, TCR?d, NK1.1 for lymphoid cell populations (further panel information and gating strategies are displayed in the Methods section and supplemental material, respectively). Representative immunofluorescence images are displayed from the corpus (CS) regions: (B) total macrophages (F4/80+, red), located in the interstitial, intraepithelial, and peritubular compartments, (C) monocytes (Ly-6C+), located in the peritubular compartment, (D and E) conventional dendritic cells cDC 1 (Clec9a+) and 2 (DC-Sign/CD209a+), (F) NK cells (NK1.1+ for flow cytometry and NCR1 for immunostaining), located in the intraepithelial compartment, (G) B cells (B220/CD45R+ for flow cytometry and CD19+ for immunostaining), (H) T cells that were further segregated into aß T cells (TCRß+, red) and ?d T cells (TCR?d+, green), scale bar 20 µm.