Table 1:

Drosophila Midgut-derived Signals

Name	Location	Cell type	Target	Target tissue	Target pathway	Type of signal	Reference
Tachykinin		EE	TkR99D	Midgut (ECs)	SREBP inhibition	Paracrine	[19]
Neurotensin	Midgut	EE	NTR	Multiple tissues	AMPK	Paracrine/endocrine	[20]
Allatostatin A	Midgut	EE	AstA-R2	CC and brain (IPCs)	AKH and insulin secretion	Paracrine/endocrine	[21,22]
Bursicon alpha	Midgut	EE	Lgr2	CC	AKH secretion	Paracrine/endocrine	[23]
CCHamide2	Midgut	EE	CCHa2-R	Brain (IPCs)	Insulin production	Endocrine	[24,25]
IMPL2	Midgut	–	Insulin-like peptide	Multiple tissues	Insulin signaling	Endocrine	[27,28]
Limostatin	Foregut	CC	LstR	Brain (IPCs)	Insulin secretion	Endocrine	[13]
AKH	Foregut	CC	AKHR	Multiple tissues	AKHR signaling	Endocrine	[5,12]
Acetic acid	Midgut lumen	Acetobacter p.	–	Multiple tissues	Insulin signaling	–	[30]
Acetate	Midgut lumen	U/l microbiota	IMD/tachykinin	Multiple tissues	Insulin signaling	–	[31•]
Amino acids	Midgut lumen	LactobacMus P.	–	Multiple tissues	TOR signaling	–	[32]

IMPL2 - Imaginal morphogenesis protein-late 2; AKH - Adipokenetic hormone; EE – Enteroendocrine; EC - Enterocyte; CC - Corpora cardiaca: TkR99O - Tachykinin receptor 99D; NTR - Neurotensin receptor; AstA-R2 - Allatostatin A receptor R2; LstR - Limostatin receptor; AKHR -Adipokenetic hormone receptor; IMD - Immune deficiency pathway; IPC - Insulin producing cells; SREBP - Sterol regulatory element binding protein; Acetobacter p. – pomorum; U/I – Unidentified; Lactobacillus p. - plantarum: AMPK - 5′ AMP activated kinase; TOR - Target of rapamycin.