Zeng Baosheng, Grayson Haley, Sun Jianjun
Department of Physiology & Neurobiology, University of Connecticut, Storrs, CT 06269, USA.
Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA.
Development. 2025 May 1;152(9). doi: 10.1242/dev.204464. Epub 2025 Apr 29.
Clearance of dying cells is essential for tissue homeostasis and requires both professional and non-professional phagocytes; however, it is unclear what promotes phagocytosis by non-professional phagocytes. Follicle cells of Drosophila egg chambers function as non-professional phagocytes to clear large germ cell debris in mid and late oogenesis, providing an excellent model for the study of non-professional phagocytes. Here, we demonstrate that GATA factor Serpent (Srp) plays an indispensable role in promoting the phagocytic capacity of follicle cells in both processes. Srp is upregulated in follicle cells of degenerating mid-stage egg chambers, and its knockdown results in incomplete clearance of germ cell debris and premature follicle cell death. In addition, Srp is upregulated in stretch follicle cells and is essential for clearing the nurse cell nuclei in late oogenesis. Genetic analysis reveals that Srp acts downstream of JNK signaling to upregulate the expression of the phagocytic receptor Draper as well as other components in the corpse processing machinery. Our findings highlight the crucial role for Srp in non-professional phagocytes during Drosophila oogenesis, which may also be conserved across species.
清除濒死细胞对于组织稳态至关重要，这需要专业和非专业吞噬细胞的参与；然而，尚不清楚是什么促进了非专业吞噬细胞的吞噬作用。果蝇卵室的滤泡细胞作为非专业吞噬细胞，在卵子发生的中期和后期清除大量生殖细胞碎片，为研究非专业吞噬细胞提供了一个极佳的模型。在这里，我们证明GATA因子Serpent（Srp）在这两个过程中促进滤泡细胞的吞噬能力方面发挥着不可或缺的作用。Srp在退化中期卵室的滤泡细胞中上调，其敲低会导致生殖细胞碎片清除不完全和滤泡细胞过早死亡。此外，Srp在伸展滤泡细胞中上调，对于卵子发生后期清除滋养细胞核至关重要。遗传分析表明，Srp在JNK信号下游起作用，以上调吞噬受体Draper以及尸体处理机制中其他成分的表达。我们的研究结果突出了Srp在果蝇卵子发生过程中非专业吞噬细胞中的关键作用，这在物种间可能也是保守的。
