Fig 5.

Restoration of melanin repression and capsule production by exogenous cAMP in tsp2-1Δ. (A) Addition of cAMP to the media restored the inhibition of melanin in the mutant tsp2-1Δ. Less pigmentation was achieved with increasing concentrations of cAMP added. Cells were incubated on 2% glucose Asn agar containing NE, with or without cAMP, at 30°C for 24 h (0, 2.5, 5, or 10 mM). (B) Likewise, 10 mM cAMP restored capsule production in tsp2-1Δ. The mutant strain tsp2-1Δ produced significantly less capsule (second image from the left). The complemented strain restored capsule production. Cells were incubated on 2% glucose Asn agar supplemented with 10 mM cAMP at 30°C for 5 days. Capsules were observed by India ink staining microscopy.