Differential gene expression by Paracoccidioides brasiliensis in host interaction conditions: Representational difference analysis identifies candidate genes associated with fungal pathogenesis

Preferential transcription of Paracoccidioides brasiliensis genes: host niche and time-dependent expression

“…By analyzing the most redundant ESTs obtained from cDNAs of yeast cells recovered from the livers of infected mice, it was possible to obtain insight into the features of fungal metabolism during the infective process in tissues (Bailão et al 2006, Costa et al 2007. Fig.…”

“…3. The degradation of fatty acids through β-oxidation could be inferred, since all gene homologues encoding enzymes in this pathway were up-regulated following exposure to blood and plasma (Bailão et al 2006. Interestingly, induction of methylcitrate genes such as the transcript encoding to 2-methylcitrate dehydratase (E.C.4.2.1.79) (which converts methylcitrate to methylisocitrate) was observed.…”

“…3). The over-expression of genes related to iron uptake has been demonstrated in the cDNA libraries of yeast cells recovered from liver of infected mice (Bailão et al 2006, Costa et al 2007 and of yeast cells incubated with human blood or plasma (Bailão et al 2006, suggesting that P. brasiliensis experiences iron deprivation under those conditions. Iron, which is a metal prominently involved in the transfer of electrons during metabolism, is of great importance to the virulence of mammalian pathogens.…”

“…One approach used to analyzing P. brasiliensis gene expression in host-like conditions involves using cDNA Representational Difference Analysis (cDNA-RDA) Hubank & Schatz 1994) to identify P. brasiliensis genes induced during the infective process in a mouse model of infection and under conditions that mimicked the hematogenic route of fungal dissemination (Bailão et al 2006), as well as infection sites with inflammation ). Subtracted cDNA libraries were made using driver cDNAs from seven-day-old yeast cell cultures and tester cDNAs were synthesized from fungal cell RNAs recovered from the liver of infected animals and from yeast cells after artificial infection with human blood or plasma.…”

“…1. A total of 45, 86 and 99 over-expressed sequences were obtained from the subtracted cDNA libraries of yeast cells recovered from infected liver (Bailão et al 2006) and from yeast cells incubated with human blood or plasma (Bailão et al 2006, respectively, as shown in Fig. 1.…”