Ca gup1Δ null mutation leads to aberrant colony morphology, precluding filamentous growth. (A) In both YPD and Spider medium, Cagup1Δ null mutant strain colonies are wrinkled (spaghetti/flower shaped) with no peripheral filamentous growth - panels I and III. The contour of these colonies observed with LM, fully confirms this absence, in clear contrast with wt and CF-Ca001 colonies - panels II and IV. (B) Growth on YPD supplemented with 10% FBS at 37°C yields identical results: colony morphology by magnifying lens (I) and by LM (II), colony contour morphology by LM (III), colony internal structure by LM (IV), and individual cells morphology by LM (V, VI). The gup1Δ photos are representative of the results obtained with the several clones (3-5) of Cagup1Δ null mutant strain tested.