Autophagy in Development and Differentiation.

Autophagy is crucial in the differentiation and development of both mammals and invertebrates, as a rapid response to environmental and hormonal stimuli. Autophagy is also important for intracellular renewal, maintaining the health of terminally differentiated cells. Studies of Drosophila, Caenorhabditis elegans, and other species revealed abnormal autophagy lead to developmental and differential abnormality, including those in salivary glands and midgut development, protein aggregation, removal of apoptotic cell corpses, and development of dauer and synapse. Autophagy also participates in the development of mammalian embryos before implantation into the uterus, adaption to the nascent hunger environment, blood cells production, and cell differentiation in adipogenesis. Autophagy found in various stem cells, like hematopoietic stem cells, bone marrow mesenchymal stem cells and neural stem cells (NSCs), is tightly associated with their self-renewal, directed differentiation, and senescence.