CGRP-Crlr/Ramp1 signal is not an important factor for maintenance of hematopoietic cells under steady-state conditions. (a,b) Relative expression levels of Crlr and Ramp1 mRNA in purified BM-derived hematopoietic subsets, including LSK, CMP, MEP, GMP, myeloid, and lymphoid cells, as assessed by quantitative real-time RT-PCR. Data are shown as means ± SD for triplicate reactions. *p < 0.05, ****p < 0.0001 compared with LSK or Ramp1 (Ordinary one-way ANOVA and Dunnett’s multiple comparisons test). (c) The percentages of Crlr or Ramp1 positive cells in purified BM-derived hematopoietic subsets, including LSK, lineage negative cells, BMMNCs, and Gr-1+CD11b+ cells, as assessed by flow cytometry. Data are shown as means ± SD of five mice. ****p < 0.0001 compared with LSK (Ordinary one-way ANOVA and Dunnett’s multiple comparisons test). A representative gating strategy is provided in Supplemental Fig. S1. (d) Intracellular cAMP concentrations in LSK cells were measured 10 minutes after treatment with or without 100 nM CGRP. ***p < 0.001 compared with control (Student’s t test). (e) The WBC, RBC, and PLT counts in the PB of Ramp1−/− and WT mice at 8 to 12 weeks of age. (f) The percentages of differentiated white blood cells (myeloid cells, B cells, and T cells) in PB from Ramp1−/− and WT mice. Data are shown as means ± SD of five mice. (g) The percentages of differentiated white blood cells (myeloid cells, B cells, and T cells) in BMMNCs cells from Ramp1−/− and WT mice. Data are shown as means ± SD of five mice. (h) Absolute numbers of BMMNCs in the BM of Ramp1−/− and WT mice. Data are shown as means ± SD of five mice. (i) Absolute numbers of immature hematopoietic subpopulations (HSC, MPP, CMP, GMP, and MEP) in the BM of Ramp1−/− and WT mice. Data are shown as means ± SD of five mice.