Mesenchymal Stromal Cells Facilitate Tip Cell Fusion Downstream of BMP-Mediated Venous Angiogenesis-Brief Report.

Background: The goal of this study was to identify and characterize cell-cell interactions that facilitate endothelial tip cell fusion downstream of BMP (bone morphogenic protein)-mediated venous plexus formation.

Methods: High resolution and time-lapse imaging of transgenic reporter lines and loss-of-function studies were carried out to study the involvement of mesenchymal stromal cells during venous angiogenesis.

Results: BMP-responsive stromal cells facilitate timely and precise fusion of venous tip cells during developmental angiogenesis.

Yap is required for scar formation but not myocyte proliferation during heart regeneration in zebrafish.

Aims: The Hippo signalling pathway regulates multiple cellular processes during organ development and maintenance by modulating activity of the transcriptional cofactor Yap. Core components of this pathway are required for neonatal mouse heart regeneration, however, investigations to date have typically focused on expression and activity in cardiomyocytes. Due to the regenerative capacity of zebrafish and the fact that global loss of Yap is not fully embryonic lethal in zebrafish, we leveraged a yap null mutant to investigate the impact of constitutive Yap deletion during zebrafish heart regeneration.