Phagocytosis is important for eliminating pathogens and dying cells and recycling cellular components. There are ‘professional phagocytes’, such as macrophages, neutrophils and dendritic cells, and ‘non-professional phagocytes’, such as epithelial cells. The GATA-family of transcription factors are known to regulate professional phagocyte function, but it is unclear whether they also promote phagocytosis in non-professional phagocytes. In this new study, Jianjun Sun and colleagues demonstrate that the GATA factor Serpent (Srp) promotes the phagocytic capacity of follicle cells - non-professional phagocytes - during Drosophila oogenesis. Using immunostaining of Srp and a reporter line, the researchers observe that Srp is upregulated in follicle cells of degenerating egg chambers upon starvation. Knockdown of srp leads to follicle cell death but incomplete clearance of germline debris. Then, the researchers conduct genetic analyses and deduce that Srp acts downstream of JNK signalling to regulate the expression of Draper (Drpr), a phagocytic receptor, and other components of the phagocytic pathway. In addition, Srp is upregulated in stretch follicle cells, which induce developmental nurse cell death, and is required for clearing debris during late oogenesis. Together, the findings support the crucial role of Serpent in stress-induced and developmental cell death processes by non-professional phagocytes during Drosophila oogenesis.
