Figure 2.
Atg1 expression leads to reduced cell size.
(A-D) Growth effects of Atg1 loss of function in wing disc clones. Pdk1 mutant clones (loss of GFP) display decreased clone size relative to the wild type twin spot (increased GFP) (A). Simultaneous loss of Atg1 (B) fails to rescue this reduction in size. Atg1 mutant clones do not display a growth phenotype when grown on normal medium (C), but growth on medium containing 2 μM rapamycin gives the Atg1 mutant clones a relative growth advantage over wild type (D).
(E) Quantitation of relative clone size in wing discs. Mean clone size normalized to wild type twin spot within the same image. Dotted line indicates a 1:1 ratio (no growth phenotype). †† indicates no significant difference from Pdk1 mutant clones: p = 0.44; † indicates an insignificant difference from wild type twinspot: p = 0.28; * indicates a significant difference from wild type twinspot: p = 0.016. n indicates clone number.
(F-H) Cell size effects of Atg1 in the fat body. Clonal loss of Atg1 function (loss of GFP, arrowheads) has no effect on fat body cell size in normally fed animals (F), but results in a relative growth advantage in animals starved of all nutrients for 45 hr (G). Clonal overexpression of Atg1 (GFP positive cells, arrowhead) (H) results in a marked reduction in cell size. Actin cytoskeleton (red) is labeled with phalloidin (F-G) or alpha-spectrin antibody (H), nuclei are marked in blue. DNA channel in (H) shows two representative confocal sections. Insets show phalloidin (or alpha-spectrin) channels of respective images.
(I) Quantitation of relative cell size in fat body. Mean cell size normalized to wild type (homozygous and heterozygous) cells within the same image. Wild type column includes cells from both fed and starved animals. † indicates no significant difference from wild type: p = 0.54; * indicates a significant difference from wild type: p < 0.0001. n indicates cell number.
Scale bars represent 10 μm. Error bars indicate SD.
Genotypes: (A) hsflp/+; Pdk15 FRT80B/Ubi-GFP FRT80B. (B) hsflp/+; Pdk15 Atg1Δ3D FRT80B/Ubi-GFP FRT80B. (C-D) hsflp/+; Atg1Δ3D FRT80B/Ubi-GFP FRT80B. (E) As in panels A-D. (F-G) hsflp/+; Cg-GAL4/+; Atg1Δ3D FRT80B/UAS-2x eGFP FRT80B. (H) hsflp/+; Act>CD2>GAL4 UAS-GFP/UAS-Atg16B. (I) As in panels F-H.