Zebrafish Flt1 Antibody / Vegfr1 / Vegf receptor 1

Zebrafish Flt1 is expressed in endothelial cells and is involved in the regulation of blood vessel formation by modulating VEGF signaling. Unlike its counterpart Kdrl (zebrafish VEGFR-2), which promotes angiogenic signaling, Flt1 primarily functions as a decoy receptor that binds VEGF-A and VEGF-B with high affinity, thereby fine-tuning angiogenic responses during embryogenesis. Zebrafish also express a soluble form of Flt1 (sFlt1), which lacks the intracellular kinase domain and acts as a natural inhibitor of VEGF signaling. Expression of flt1 in zebrafish is detected early during embryonic development, particularly in developing vasculature such as the dorsal aorta, cardinal vein, and intersegmental vessels. Disruption of flt1 leads to aberrant vessel patterning and excessive endothelial sprouting, highlighting its essential regulatory function in vascular morphogenesis. Due to the optical transparency of zebrafish embryos and the availability of vascular reporter lines, zebrafish Flt1 serves as a powerful model for studying angiogenesis, vascular remodeling, and the mechanisms of VEGF signaling in vivo. It is also a valuable tool for investigating vascular defects, cancer biology, and responses to anti-angiogenic therapies.