Table 1.

Glia engulf neurons and neural fragments in several contexts^a

Context	System	Ligand	Glia	Receptor	Effectors	References
Development	Development and metamorphosis (Drosophila)	PS, Toll-6	Surface glia, neuropil glia, cell body glia, peripheral glia, astrocyte	CED-1/Draper; SIMU/Stabilin2; Toll receptor	CED-2/CrkII; CED-5/Mbc; dCED-12; dCED-6/GULP; dSARM	Cantera and Technau, 1996; Awasaki and Ito, 2004 Watts et al., 2004; Kurant et al., 2008; Tasdemir-Yilmaz and Freeman, 2014; Etchegaray et al., 2016 McLaughlin et al., 2019
	Neuromuscular junction (mouse)	?	Terminal Schwann cells	?	?	Bishop et al., 2004; Song et al., 2008; I.W. Smith et al., 2013
	Retina (mouse)	C1q	Microglia	Csf1r	?	Anderson et al., 2019
	dLGN (mouse)	PS, neuron activity	Astrocyte	CED-1/MEGF10	?	Chung et al., 2013
		PS, CD47, C1q, IL33, C3	Microglia	CR3, GPR56, IL1RL1	?	Stevens et al., 2007; Schafer et al., 2012; Lehrman et al., 2018; Vainchtein et al., 2018; T. Li et al., 2020; Scott-Hewitt et al., 2020
	Hippocampus (mouse)	PS, C1q, CX3CL1 (fractalkine)	Microglia	TREM2, CX3CR1	P38/MAPK; cytokine signaling	Paolicelli et al., 2011;b Filipello et al., 2018; Scott-Hewitt et al., 2020
Function	Retina (mammals)	PS, Gas6	RPE glia-like cell	MeRTK, integrins	CED-10/Rac1 GTPase, FAK	Finnemann and Silverstein, 2001; Feng et al., 2002; Finnemann, 2003; Mao and Finnemann, 2012
	Hippocampus (mouse)	C1q	Microglia	?	?	C. Wang et al., 2020
Injury	Nerve injury (Drosophila)	Insulin-like peptides	Ensheathing glia	CED-1/Draper, insulin-like receptor	CED-12/Crk/Mbc/dCED-12; DRK/DOS/SOS; CED-10/Rac1 GTPase; STAT92E; AP-1	MacDonald et al., 2006; Doherty et al., 2009, 2014; Ziegenfuss et al., 2012; Lu et al., 2014; Musashe et al., 2016
	Striatum ischemia (mouse)	PS	Microglia	CED-7/ABC1	?	Morizawa et al., 2017
	Cortex injury (mouse)	ATP	Astrocyte		?	Burda et al., 2017

^aWork in multiple systems highlights relevant molecules and mechanisms by which glia engulf in development, neural function, and following injury (summarized here).

^bFractalkine signaling; also, other brain regions not listed.