HISTOLOGY AND HISTOPATHOLOGY

From Cell Biology to Tissue Engineering

 

Analysis of wt1a reporter line expression levels during proepicardium formation in the zebrafish

Laura Andrés-Delgado1,2, María Galardi-Castilla2, Nadia Mercader2,3 and Luis Santamaría1

1Department of Anatomy, Histology and Neuroscience, School of Medicine, Autonoma University of Madrid, 2Development of the Epicardium and its Role During Regeneration Laboratory, Nacional Center of Cardiovascular Research Carlos III, Madrid, Spain and 3Institute of Anatomy, University of Bern, Bern, Switzerland

Offprint requests to: Laura Andrés-Delgado, PhD, Departamento de Anatomía, Histología y Neurociencia, Facultad de Medicina, Universidad Autónoma de Madrid, C/ Arzobispo Morcillo, 4, 28029 Madrid, Spain. e-mail: laura.andresd@uam.es


Summary. The epicardium is the outer mesothelial layer of the heart. It covers the myocardium and plays important roles in both heart development and regeneration. It is derived from the proepicardium (PE), groups of cells that emerges at early developmental stages from the dorsal pericardial layer (DP) close to the atrio-ventricular canal and the venous pole of the heart-tube. In zebrafish, PE cells extrude apically into the pericardial cavity as a consequence of DP tissue constriction, a process that is dependent on Bmp pathway signaling. Expression of the transcription factor Wilms tumor-1, Wt1, which is a leader of important morphogenetic events such as apoptosis regulation or epithelial-mesenchymal cell transition, is also necessary during PE formation. In this study, we used the zebrafish model to compare intensity level of the wt1a reporter line epi:GFP in PE and its original tissue, the DP. We found that GFP is present at higher intensity level in the PE tissue, and differentially wt1 expression at pericardial tissues could be involved in the PE formation process. Our results reveal that bmp2b overexpression leads to enhanced GFP level both in DP and in PE tissues. Histol Histopathol 35, 1035-1046 (2020)

Key words: Zebrafish, Pericardial tissues, Cavalieri's volume estimation, Bmp signaling

DOI: 10.14670/HH-18-238