Table 1.

Evidence for and against adult neurogenesis in Drosophila. Summary of findings reported in the review, that either support adult neurogenesis or not.

Evidence of Adult Neurogenesis		Evidence Against Adult Neurogenesis
Finding	Reference	Finding	Reference
Cell Proliferation
Cycling cells detected in S-phase with 3H-Thymidine, BrdU, EdU, PCNA-GFP and FUCCI; in G1, with FUCCI; in G2, G2/M were revealed with FUCCI, nuclear Stg-GFP and Yki-GFP.	[6,33,34,35,37]	BrdU incorporation not detected in adult and PCNA-GFP was not seen after 96h APF.	[2,3,27]
		Polyploidy in the adult brain.	[38]
Inference of mitosis from MARCM clones. Clones induced in the adult brain generated both glial and neuronal progeny cells. Incidence of clones increased with flippase-induced recombination compared to controls. Some clones were BrdU+.	[34,35,36,37]	No MARCM clones detected in normal adult brains	[6,27]
		MARCM clones were detected in control brains that had not been heat-shocked, and Twin-Spot based approaches may not guarantee reporter knock-down	[34,35,36]
Inference of mitosis: A BrdU pulse in the adult resulted in multiple labelled progeny cells over time.	[34,35,37]
Injury, Neuronal Activity and Altered Gene Function Can Increase Cell Proliferation
Injury increased proliferation in central brain and optic lobes (BrdU, MARCM)	[34,36]
Altering gene function can increase cell number, proliferation (various methods, including pH3) or brain size: dMyc, miR-31a, Toll-2, wek, MyD88, yki	[6,36,37]
Activating neurons increases cell number	[6]
Gliogenesis and neurogenesis
Gliogenesis: Repo+ BrdU+ cells in MARCM clones, after injury, alterations in gene expression and lineage tracing of inscGAL4 in the adult brain.	[34,35,37]
Neurogenesis: Perma-Twin MARCM Elav+ clones, MARCM together with Toll-2 over-expression and lineage tracing with inscGAL4 in adult brain.	[6,36,37]
Neuroblasts/neural stem cells
Potentially unknown Type II NB INPs and progeny cells	[9,14,15,23]	Developmental neuroblasts are eliminated before adult eclosion	[24,25,27,28,29]
Cells with NB markers Dpn, Mira, Ey, worGAL4 and inscGAL4 in the adult brain. InscGAL4 with lineage tracing in adult produced both neurons and glia	[6,36,37,49]	Dpn+, Mira+ and Pros+ cells disappear after pupa	[27]
RNAseq analysis revealed NB genes expressed in the adult brain	[50,51,52]	Typical NB genes can have pleiotropic functions	[50,51]
Missing evidence	Seeing dividing cells with pH3, other mitotic markers or time-lapse films Identification of adult progenitor cells, origin, model of cell division and resulting progeny cells