• B-Mrc1-EGFP-DTR-Luciferase mice have the endogenous mouse Mrc1 promoter to determine the expression of DTR (Diphtheria toxin receptor), EGFP (enhanced green fluorescent protein) and luciferase.
• Mrc1+ macrophages cells were traced by EGFP in B-Mrc1-EGFP-DTR-Luciferase mice, and could be effectively eliminated after DT administration.

Frequency of leukocyte subpopulations in spleen by flow cytometry. Splenocytes were isolated from wild-type C57BL/6JNifdc mice (female, n=3, 6-7-week-old) and heterozygous B-Mrc1-EGFP-DTR-Luc mice (female, n=3, 6-7-week-old). Flow cytometry analysis of the splenocytes was performed to assess the frequency of leukocyte subpopulations. Percentages of T cells, B cells, NK cells, dendritic cells, monocytes, macrophages, and granulocytes in B-Mrc1-EGFP-DTR-Luc mice were similar to those in C57BL/6JNifdc mice. Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***p < 0.001.

Frequencies of MRC1+ cells in peritoneal lavage fluid by flow cytometry. Peritoneal lavage fluid was isolated from wild-type C57BL/6JNifdc mice (+/+) and heterozygous B-Mrc1-EGFP-DTR-Luciferase mice (Mut/+) injected with DT (20 ng per g body weight) for one day. Flow cytometry analysis of the peritoneal lavage fluid was performed to assess the frequencies of MRC1+ cells in CD11b-low cells, large peritoneal macrophages (LPMs) and small peritoneal macrophages (SPMs). The signal for MRC1+ cells in CD11b-low cells (A), SPMs (B) and LPMs (C) were significant decreased in heterozygous mice injected with DT.

Frequencies of EGFP cells in peritoneal lavage fluid by flow cytometry. Peritoneal lavage fluid was isolated from wild-type C57BL/6JNifdc mice (+/+) and heterozygous B-Mrc1-EGFP-DTR-Luciferase mice (Mut/+) injected with DT (20 ng per g body weight) for one day. Flow cytometry analysis of the peritoneal lavage fluid was performed to assess the frequencies of EGFP+ cells in CD11b-low cells, large peritoneal macrophages (LPMs) and small peritoneal macrophages (SPMs). The signal for EGFP+ cells in CD11b-low cells (A), SPMs (B) and LPMs (C) were significant decreased in heterozygous mice injected with DT.