Figure 3: In unwounded epidermis, basement membrane proteins come from other tissues.

A) Experiment overview: tissue expressing a basement membrane protein allele fused to GFP (BM-GFP) and an allele not fused with GFP will secrete both forms for incorporation into the basement membrane, resulting in fluorescent basement membrane. When dsRNA^GFP targets GFP in the source tissue, only the basement membrane protein lacking GFP will be secreted, resulting in non-fluorescent basement membrane. B) Example images without (top) and with (bottom) dsRNA^GFP expression. Scale bar, 50 µm. C-E) Laminin-GFP, collagen IV-GFP, or perlecan-GFP is lost from the epidermal BM when dsRNA^GFP is expressed in adipose tissue. F) Nidogen-GFP is lost from the epidermal BM when dsRNA^GFP is expressed in the muscles. *** indicates p ≤ 0.001.