Figure 4

Ths and Pyr truncation constructs that support the production of secreted proteins in cell culture are also functional in the embryo. (A) Stage 11, wild type embryos, lateral view, stained with anti-Eve antibody show Eve-positive staining in three cells per hemisegment. The enlargement of the Eve-positive area is 1.8x. (B-I) pUASt-HA-Ths and pUASt-HA-Pyr full-length and truncated construct schematics; assay for secretion was conducted in S2 cell culture. Embryos overexpressing indicated constructs with 69B-GAL4 were stained with anti-Eve antibody to score for FGF activity. (B) Overexpression of full-length Ths results in more Eve-positive cells (Eve+++). (C, E) HA-Ths^1-158 and HA-Ths^1-403 are both secreted and Eve +++, but (D) HA-Ths^1-261 is not secreted and does not support more Eve-positive cells. (F) Overexpression of full length Pyr also results in Eve+++. (G) HA-Pyr^1-220 is not secreted and does not give more Eve-positive cells, but (H, I) HA-Pyr^1-348 and HA-Pyr^1-466 are both secreted and exhibit the Eve+++ phenotype.