Pbx4 is Required for the Temporal Onset of Zebrafish Myocardial Differentiation

Journal of Developmental Biology

Robert M. Kao¹  Joel G. Rurik¹  Gist H. Farr¹  Xiu Rong Dong¹  Mark W. Majesky¹  Lisa Maves¹  Robert W. Dettman² 

[1] Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, 1900 9th Avenue, Seattle, WA 98101, USA; E-Mails:Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, 1900 9th Avenue, Seattle, WA 98101, USA;

关键词: cardiomyocyte;    differentiation;    myocardial morphogenesis;    outflow tract;    proepicardium;    zebrafish;    pbx4;   

DOI  :  10.3390/jdb3040093

来源: mdpi

【 摘 要 】

Proper control of the temporal onset of cellular differentiation is critical for regulating cell lineage decisions and morphogenesis during development. Pbx homeodomain transcription factors have emerged as important regulators of cellular differentiation. We previously showed, by using antisense morpholino knockdown, that Pbx factors are needed for the timely activation of myocardial differentiation in zebrafish. In order to gain further insight into the roles of Pbx factors in heart development, we show here that zebrafish pbx4 mutant embryos exhibit delayed onset of myocardial differentiation, such as delayed activation of tnnt2a expression in early cardiomyocytes in the anterior lateral plate mesoderm. We also observe delayed myocardial morphogenesis and dysmorphic patterning of the ventricle and atrium, consistent with our previous Pbx knock-down studies. In addition, we find that pbx4 mutant larvae have aberrant outflow tracts and defective expression of the proepicardial marker tbx18. Finally, we present evidence for Pbx expression in cardiomyocyte precursors as well as heterogeneous Pbx expression among the pan-cytokeratin-expressing proepicardial cells near the developing ventricle. In summary, our data show that Pbx4 is required for the proper temporal activation of myocardial differentiation and establish a basis for studying additional roles of Pbx factors in heart development.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.