Generation of transgenic zebrafish with liver-specific expression of EGFP-Lc3: a new in vivo model for investigation of liver autophagy.

Transgenic expression of GFP-Lc3 is a useful tool for an in vivo model to monitor the formation of autophagosomes during the autophagy process. So far, two transgenic animals (mice and zebrafish) with expression of GFP-Lc3 have been reported. Liver is one of the most important organs for autophagy research. Here, we generated a transgenic zebrafish line with liver-specific EGFP-Lc3 expression. By exposing transgenic larvae to the autophagy inducer, Torin1, we observed a substantial increase in the number of EGFP-Lc3 puncta in the liver as well as the increase of Lc3-II protein. Notably, addition of a chloroquine (CQ) led to further increase of EGFP-Lc3 puncta in liver cells due to the blockage of lysosomal function and degradation stage of autophagy. Thus, the newly established transgenic line will be a useful in vivo model to investigate liver autophagy, and, in particular, the involvement of autophagy in basic biology and diseases in the liver.