Figure 3. α^a strains fuse with wild-type α cells.

(A) Sexual development assays were carried out on V8 media using differentially labeled a and α strains (red or green) to detect the formation of germ tubes (by α cells) and fusants (dumbbell shaped structures). A representative view from the indicated cross is displayed in each panel (1-8). In panels 1–4, a cells are labeled red, and α cells are labeled green. Panel 1: wild type a x α fusant. Panel 2: germ tube from an α^mfαΔ cell; no fusants. Panels 3 and 4: no germ tubes; no fusants. In panel 5, wild type α cells are labeled red or green. In panels 6–8, wild type α cells are labeled red and modified α cells are labeled green. Panels 5–7: no germ tubes; no fusants. Panel 8: wild type α x α^a fusant. (B) α^a cells do not form germ tubes. Wild type α cells were labeled red, and α^a cells were labeled green. Wild type α cells (red) produce germ tubes in response to a cells (A, panel 1) and to α^a cells (A, panel 8). Similar to wild-type a cells, α^a cells do not form germ tubes in response to α cells.