Starvation-sensitivity assays define the range of autophagy defects in <i>vap</i> flies.

<p>The survival rate of 3 day-old adult males of indicated genotypes was recorded at 25°C in condition of complete food deprivation (see <b><a href="" target="_blank">S4A–S4C Fig</a></b> for initial characterization). (A) The <i>vap</i>-dependent starvation sensitivity (white arrow) was compared to weak (<i>Atg8a</i><sup><i>1</i></sup>) and strong (<i>Agt8a</i><sup><i>2</i></sup>) alleles of <i>Atg8</i>a. <i>Atg8a</i><sup>2</sup> flies showed slightly altered development that might contribute to its greater sensitivity to starvation. (B-B’) Starvation sensitivity effect, as assayed at 25°C, is partially recapitulated by flies that were ectopically expressing an <i>UAS-myc</i>:<i>Atg1</i> transgene (Materials and Methods) along fat cell development performed at 25°C (white arrow in B) when driven by <i>cg-Gal4</i>. As a control, there is no detectable starvation sensitivity (as assayed at 25°C) using identical flies (<i>UAS-myc</i>:<i>Atg1</i> /<i>cg-Gal4</i>) that developed at 18°C to minimized transgene expression (white arrow in B’). Ectopic expression of <i>Atg1</i> during development is therefore responsible for the sensitivity effect found in B. (C) The <i>vap</i>-dependent starvation sensitivity is suppressed (white arrow) by co-expressed <i>Atg5(RI)</i> using the broadly expressed <i>arm-Gal4</i> driver. Genotypes. (A) Control: <i>w</i><sup><i>1118</i></sup><i>/Y</i>. Assay <i>vap</i><sup><i>1</i></sup><i>/Y</i>. <i>Atg8a</i><sup><i>1</i></sup><i>/Y</i>. <i>Atg8a</i><sup><i>2</i></sup><i>/Y</i>. (B, B’) Control: <i>UAS-myc</i>:<i>Atg1/+</i> and <i>vap</i><sup><i>1</i></sup><i>/Y</i> and <i>vap</i><sup><i>1</i></sup><i>/Y; cg-GAL4/+</i>. Assay: <i>vap</i><sup><i>1</i></sup><i>/Y</i>. <i>cg-GAL4/ UAS-myc</i>:<i>Atg1(RI)/+</i>. (C) Control: <i>arm-GAL4/+</i> and <i>vap</i><sup><i>1</i></sup><i>/Y; arm-GAL4/+</i> and <i>arm-GAL4/ UAS-Atg5(RI)/+</i>. Assay: <i>vap</i><sup><i>1</i></sup><i>/Y; arm-GAL4/ UAS-Atg5(RI)/+</i>.</p>