MC5R is abundantly enriched in HSPCs but dispensable for steady-state hematopoiesis. (A) Expression value of MC1R, MC2R, MC3R, MC4R, and MC5R in LSKs sorted from healthy WT mice (n = 3). The data were obtained from our previous study (GSE173291). (B) qRT-PCR analysis of MC5R expression in LSKs, SLAM-HSCs, long-term HSCs (LT-HSCs), short-term HSCs (ST-HSCs), multipotent progenitors (MPPs), myeloid progenitors (MPs), common myeloid progenitors (CMPs), granulocyte monocyte progenitors (GMPs), megakaryocyte erythroid progenitors (MEPs), common lymphoid progenitors (CLPs), Lineage^– (Lin^–) cells, and Lin⁺ cells sorted from the BM of healthy WT mice (n = 3). The relative expression of MC5R was compared with that in Lin⁺ cells. (C) Representative immunofluorescence plots showing MC5R expression in LSKs, MPs, and Lin⁺ cells sorted from the BM of helathy WT mice. (D) WBC, RBC, and PLT counts in the PB of WT and MC5R^–/– mice (n = 9). (E) The total number of BM cells in WT and MC5R^–/– mice (n = 6). (F) Representative flow cytometric plots showing the percentages of MPs, LSKs, LT-HSCs, ST-HSCs, and MPPs in the BM of WT and MC5R^–/– mice. (G) The number of MPs and LSKs in the BM of WT and MC5R^–/– mice (n = 6). (H) The number of LT-HSCs, ST-HSCs, and MPPs in the BM of WT and MC5R^–/– mice (n = 6). (I) Representative flow cytometric plots showing the percentage of MEPs, CMPs, GMPs, and CLPs in the BM of WT and MC5R^–/– mice. (J) The number of GMPs, CMPs, MEPs, and CLPs in the BM of WT and MC5R^–/– mice (n = 6). (K) Flow cytometric analysis of the percentage of T, B, and myeloid cells in the BM of WT and MC5R^–/–v mice (n = 6). Representative flow cytometric plots (left). (A,B) One-way ANOVA with Tukey multiple comparisons test; (D,E,G,H,J,K) unpaired t test (two-tailed). ∗P < .05; ∗∗∗P < .001. ANOVA, analysis of variance; PLT, platelet; RBC, red blood cell; WBC, white blood cell.