Identification of overlapping and distinct mural cell populations during early embryonic development

Abstract

Mural cells are an essential perivascular cell population that associate with blood vessels and contribute to vascular stabilization and tone. In the embryonic zebrafish vasculature, pdgfrb and tagln are commonly used as markers for identifying pericytes and vascular smooth muscle cells (vSMCs). However, the expression patterns of these markers used in tandem have not been fully described. Here, we used the Tg(pdgfrb:Gal4FF; UAS:RFP) and Tg(tagln:NLS-EGFP) transgenic lines to identify single- and double-positive perivascular populations in the cranial, axial, and intersegmental vessels between 1 and 5 days post-fertilization. From this comparative analysis, we discovered two novel regions of tagln-positive cell populations that have the potential to function as mural cell precursors. Specifically, we found that the hypochord, a reportedly transient structure, contributes to tagln-positive cells along the dorsal aorta. We also identified a unique sclerotome-derived mural cell progenitor population that resides along the midline between the neural tube and notochord and contributes to intersegmental vessel mural cell coverage. Together, our findings highlight the variability and versatility of tracking pdgfrb and tagln expression in mural cells of the developing zebrafish embryo.

Hemodynamics regulate spatiotemporal artery muscularization in the developing circle of Willis

“…In addition, acta2 + VSMCs on CaDI, BCA, and PCS still retain expression of pdgfrb as late as 6 dpf ( Ando et al, 2021 ). Thus, it is possible that stable expression of klf2a in CoW arterial ECs supports further VSMC maturation, as indicated by expression of tagln ( Colijn et al, 2023 ). Another aspect of VSMC maturation is its function to confer vascular tone.…”

Hemodynamics regulate spatiotemporal artery muscularization in the developing circle of Willis

“…Interestingly, acta2 + VSMCs on CaDI, BCA, and PCS still retain expression of pdgfrb at 6 dpf (Ando et al, 2021). Thus, it is possible that stable expression of klf2a in CW arterial ECs will support later on complete VSMC maturation, for example in Transgelin positive cells (Colijn, Nambara, & Stratman, 2023). Alternatively, acta2 + VSMCs with pdgfrb expression are maintained as such in the CW arteries (Ando et al, 2021).…”

“…In addition, acta2 + VSMCs on CaDI, BCA, and PCS still retain expression of pdgfrb at 6 dpf (Ando et al, 2021). Thus, it is possible that stable expression of klf2a in CoW arterial ECs supports further VSMC maturation, as indicated by expression of tagln (Colijn, Nambara, & Stratman, 2023). Another aspect of VSMC maturation is its function to confer vascular tone.…”