(A) Diagram of the fcho-1 locus in C. elegans indicating four point mutations and two deletions associated with a loss-of-function phenotype. The targeted deletion (ox477) was generated by mobilizing the Mos1 transposon and repairing the broken chromosome with a recombinant template that replaces the first eight exons with a positive selection (unc-119 rescue). ox477 was used exclusively throughout this study as fcho(−). (B) Images of animals cropped in Figure 1A. fcho(−) and AP2 subunit(−) animals are dumpy and egg-laying defective. Red arrowheads point to jowls. (C) Diagram of artificial GFP-CD4 AP2 cargo. GFP was flanked by two 12 amino acid flexible linkers and inserted between a secretion signal peptide from C. elegans PAT-3 and a modified human CD4 truncated to include two immunoglobulin domains, the transmembrane domain, and eight amino acids from the cytoplasmic domain (Feinberg et al., 2008). The four amino acid YxxΦ motif from the C-terminus of the C. elegans lysosome-associated membrane glycoprotein, LMP-1, was appended. (D) Cargo assay (amount of GFP-tagged cargo on intestinal cell membrane). **p < 0.01, unpaired, two-tailed t-test compared to WT, n ≥ 9. (E) Brood size assay. Number of fertilized embryos produced by individual hermaphrodites of the indicated genotype. *p < 0.05, **p < 0.01, unpaired, two-tailed t-test compared to WT, n ≥ 8. Values for WT and apa-2 samples were previously published (Gu et al., 2013). (F) Starvation assay. Days required for a worm population to expand and consume the bacterial food. **p < 0.01, unpaired, two-tailed t-test compared to WT, n = 12. Data in (D), (E) and (F) represent the mean ± SEM.