Effects of miR-30c over-expression on early cardiac development of zebrafish

Abstract

Objective To explore the effects of miR-30c over-expression on early cardiac development of zebrafish. Methods The single-cell-stage zebrafish embryos were micro-injected with 3 different concentrations of miR-30c mimics in order to model the miR-30c over-expressed animal.Besides, the effects of miR-30c overexpression on cardiac development were investigated.The mortality rate and the heart rate were assessed.Beside, the gross morphology and heart morphology of the zebrafish were observed.Moreover, the molecular mechanisms underlying miR-30c function in zebrafish cardiac development was explored, and in-situ hybridization was performed. Results Compared with the wild-type embryos, the mortality rate of zebrafish was increased with the rising miR-30c concentration.Furthermore, when the miR-30c mimic concentration was up to 8 μmol/L, the mortality rate reached 80% at 96 h post-fertilization.Simultaneously, the heart rate, which was viewed as an important index to cardiac function, was decreased.Moreover, the pericardial edema was getting worse over time with increasing concentration of overexpression.Then, the cardiac specific gene expression on the zebrafish embryos by whole-mount in situ hybridization was explored.The area of the cardiac chamber was extended and the heart tube looping was negatively affected.Besides, the expression of atrioventricular canal marker genes was absent in zebrafish embryos from miR-30c over-expression groups. Conclusion miR-30c can impact the early cardiac development of zebrafish. Key words: miR-30c; Zebrafish; Cardiac development