TY - JOUR T1 - Hippo signaling restricts cells in the second heart field that differentiate into Islet-1-positive atrial cardiomyocytes JF - bioRxiv DO - 10.1101/154765 SP - 154765 AU - Hajime Fukui AU - Takahiro Miyazaki AU - Hiroyuki Ishikawa AU - Hiroyuki Nakajima AU - Naoki Mochizuki Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/06/23/154765.abstract N2 - Cardiac precursor cells (CPCs) in the first heart field (FHF) and the second heart field (SHF) present at both arterial and venous poles assemble to form a cardiac tube in zebrafish. Hippo kinase cascade is essential for proper heart formation; however, it remains elusive how Hippo signal contributes to early cardiac fate determination. We here demonstrate that mutants of large tumor suppressor kinase 1/2 (lats1/2) exhibited an increase in a SHF marker, Islet1 (Isl1)-positive and hand2 promoter-activated venous pole atrial cardiomyocytes (CMs) and that those showed expansion of the domain between between the anterior and the posterior lateral plate mesoderm. Consistently, TEAD-8 dependent transcription was activated in caudal region of the left ALPM cells that gave rise to the venous pole atrial CMs. Yap1/Wwtr1-promoted bmp2b expression was essential for Smad-regulated hand2 expression in the left ALPM, indicating that Hippo signaling restricts the SHF cells originating from the left ALPM that move toward the venous pole. ER -