FIG. 1.
Reduction of D-Fos activity interferes with normal growth. (A) Ubiquitous knockdown of D-fos mRNA during larval development results in smaller body size. Wild-type (WT) flies and flies carrying fosRNAi were crossed with flies expressing T80Gal4 and UAS EGFP. Eggs from each genotype were collected for 4 h, and larvae were raised on apple juice agar with yeast paste at 27°C. The image shows larvae of the same age. (B) Eye-specific expression of fosRNAi under the control of eyGal4 (eyG4) resulted in defective eye development with various levels of penetrance. Phenotypes range from a complete loss of the eye to an almost wild-type appearance. (C and D) The loss of D-fos in a tissue-specific manner caused a size decrease in the affected area. In the absence of a Gal4 driver, flies carrying UAS fosRNAi show no developmental defects. When fosRNAi was expressed in the wing imaginal disc under the control of the enGal4 (enG4) driver at 22°C, the emerging adult flies showed a reduced size of the posterior compartment where this driver is active (compare areas highlighted in blue). (E) When expression levels of D-Fos were suppressed throughout wing primordium development by the expression of fosRNAi under the control of sdGal4, the emerging adult wings became severely hypotrophic. (F) Compartment sizes of adult wings shown in panels C and D were measured by counting pixels in digital images by using Adobe Photoshop. Twenty adult wings per genotype were analyzed. The sections of the anterior compartment that were measured for the quantitative analyses are demarcated by L1 and L3 (marked in dark gray). The size of the area below vein L4, highlighted in blue, was calculated as a measure for posterior compartment size.