FIGURE 1

FIGURE 1

ZebraReg: a novel platform for discovering regulators of cardiac regeneration using zebrafish. (A) Overview of the timeline of the experimental procedure. The ZebraReg platform utilises the doubly transgenic Heartbreaker zebrafish line. In this zebrafish line, a tamoxifen-induced recombination and subsequent drug treatment lead to cell-specific death of a large pool of ventricular cardiomyocytes. Thus, a robust ventricular injury is caused, and is regenerated through the proliferation of the remaining cardiomyocytes. Automated imaging at six, seven and nine dpf (corresponding to timepoints TP1, TP2, and TP3) allows for the longitudinal analysis of the regenerative process. The process can be integrated with pharmacological and genetic approaches to determine the effect of genes and drugs on regeneration kinetics. In the case of pharmacological modulation, the drug treatment is performed for 24 h between TP1 and TP2. In the case of genetic modulation, a CRISPR/Cas9-based approach for generating F0 crispants is performed at one-cell stage to induce the loss of function of the gene of interest. (B) The automated imaging system consists of the VAST BioImager and LP Sampler and an integrated Leica fluorescent microscope for high resolution imaging. The systems cooperate in order to detect and image each larva. For each larva, two readouts are generated: firstly, a set of in toto images is obtained by the VAST BioImager for morphological readouts. The larva is then oriented with the ventral side facing the objective of the integrated fluorescent Leica microscope. Subsequently, the Leica microscope obtains a high-resolution time-lapse video of the heart. This video is then used to determine the size of the heart at each timepoint to determine the regeneration kinetics of each larva. The larva is then dispensed into a destination 96 well plate in the same position it was located in the source 96 well plate. Modified from Dyballa et al. (2019).