Bulk RNA-sequencing of pooled 53 hpf wild-type and iqgap1-/- hemorrhage-positive mutant embryos

Expression pattern of iqgap1 strongly overlapped with the vascular marker fli1a expression but more broadly present in tissues such as muscle, branchial arches, caudal hematopoietic tissue. Re-analysis of single-cell RNA-seq data extended the known expression pattern of iqgap1 to include mesenchyme, periderm, neural cell types, granulocytes and macrophages. Strikingly, iqgap1 showed a striking co-localization with fli1a in the brain blood vessels, whose disruption likely causes the brain hemorrhage.

RNA sequencing-based comparison of whole hemorrhage-positive iqgap1-/- embryo pools with wild-type embryos at 54 hpf shortly after the onset of hemorrhage identified 1283 differentially regulated genes. The most striking feature of this dataset was up-regulation of hematopoietic markers especially those of erythrocytes, neutrophils, mast cells and HSPCs (hematopoietic stem and progenitor cells) but macrophages were down-regulated.

We have confirmed that erythrocytes up-regulation is linked to hemorrhage. By contrast, mast cells, neutrophils are up-regulated and macrophages are reduced in iqgap1-/- embryos with or without hemorrhage.