Emerging regulatory mechanisms and functions of autophagy in fish

Autophagy is a bulk subcellular degradation process through which eukaryotic cells maintain health by forming autophagosomes and recycling intracellular substances. This particular process is an important mechanism for cell survival, growth, differentiation, development and homeostasis. Over the past few decades, studies on yeast and mammalian autophagy have greatly increased our understanding of autophagy and its relationship with human health and disease. However, our understanding of autophagy in fish cells is limited. Recent studies have made some progress in investigating the induction of autophagy in fish cells, the expression and regulation of autophagy-related genes, and the role of autophagy under conditions of pathogen infection. In particular, genetically modified zebrafish and zebrafish cell lines have been constructed as models to investigate the role of autophagy in developmental regulation, resistance to pathogen infection, lipid degradation and other physiological and pathological responses in fish. Understanding fish autophagy will aid in the prevention and treatment of related diseases by enabling the manipulation of autophagy levels in cells to improve fish health. Here, we review the most recent discoveries concerning autophagy in fish.