Characterization of hematopoietic lineages and progenitors in E14.5 FL. (A) JAM-C expression on E14.5 FL-derived hematopoietic progenitors of wild-type (black histogram line) and homozygous embryos (hatched histogram line) measured by flow cytometry (LSA). Shown is a representative histogram with rabbit serum IgG (filled gray histogram) as control. (B) Total number of cells in E14.5 FL (left plot) and hematopoietic progenitors (LSA cells, right plot) of wild type (n = 12) and homozygous (n = 11) embryos. (C) Frequencies of the different hematopoietic lineages in E14.5 FL of wild-type and homozygous embryos were measured by flow cytometry with antibodies against Gr-1 and CD11b (myeloid lineage) and Ter119 (erythroid lineage). (D) Total number of myeloid and erythroid cells in E14.5 FL of wild-type and homozygous embryos. Shown are representative FACS profiles; the numbers on the plots indicate the frequency of cells in the indicated regions. Bar graphs indicate mean plus or minus SE. (E) Colony-forming ability of E14.5 FL cells derived from wild-type (n = 12) and homozygous (n = 11) embryos cultured in methylcellulose containing mSCF, mIL-3, mIL-6, and hEPO. After 10 days in culture, colonies were assigned scores for the presence of CFU-GEMM, BFU-E, and CFU-GM. Data represent mean plus or minus SE of duplicate plates. (F) Frequency of CD45.2⁺ donor-derived BM cells 8 and 32 weeks old after the transfer of 2 × 10⁶ FL cells derived from wild-type and homozygous embryos (n = 4 in each group) into lethally irradiated BL6 hosts. Data represent mean plus or minus SE.