Tetraspanin and heat-shock cognate 3 (Hsc-3) silencing have the opposite effect, enhancing Selleckchem KU55933 infection, while reducing the expression of the solute
transporter (Sol. Trsp.) gene did not affect infection with P. berghei [12]. The effect of silencing two An. gambiae homologs of a glutathione S-transferase of the theta class (GSTT) (CG1702-PA) gene also identified in the Drosophila screen on P. berghei infection was evaluated. Injection of GSTT1 (AGAP000761-PA) or GSTT2 (AGAP000888-PA) dsRNA reduced mRNA expression by 60% and 55%, respectively, relative to the control groups injected with dsLacZ. Both GSTT1 and GSTT2 knockdown significantly reduce P. berghei infection (P < 0.05 and P < 0.03, respectively) using the Kolmogorov-Smirnov (KS) test (Figure 1 and Ilomastat research buy Table 1). Figure 1 Effect of silencing An. gambiae (G3) GSTT1 and GSTT2 on P. berghei infection. Panel A, Effect of silencing glutathione-S-transferase theta-1 (GSTT1) on Plasmodium infection. GFP-expressing parasites were counted directly 6 days post infection (PI). Panel B, Effect of silencing glutathione-S-transferase theta-2 (GSTT2) on Plasmodium infection. Infection levels were determined
based on the relative abundance of P. berghei 28S and An. gambiae S7 genes in genomic DNA isolated from midguts 6 days PI. The dots represent the infection level on individual midguts, and the median infection level is indicated by the horizontal line. Distributions are shown using a logarithmic scale for GSTT2 and are compared using the Kolmogorov-Smirnov (KS) test; n = number of mosquitoes; P values lower than 0.05 are considered to be significantly different. Table 1 Effect of silencing seven An. gambiae genes or their orthologs in An. Calpain stephensi on the intensity of P. berghei, P. falciparum or P. yoelii infection. An. gambiae Gene ID Gene An. gambiae P. berghei (21°C) An. gambiae P. falciparum (26°C) An. stephensi P. yoelii (24°C) AGAP005627 ArgK Decrease 1 Decrease AGAP010892 Sol. trsp. No effect1 No effect AGAP005233 Tetrasp. Increase
1 Increase AGAP001751 OXR1 Decrease 1 No effect No effect AGAP004192 Hsc-3 Increase 1 Decrease Increase AGAP000761 GSTT1 Decrease No effect No effect AGAP000888 GSTT2 Decrease Increase Increase AGAP006348 LRIM1 Increase 2 No effect.3 No effect AGAP005335 CTL4 Decrease 2 No effect.3 No effect 1Brandt et al., 2008 2Osta et al., 2004 3Cohuet et al., 2006 Direct comparison of the effect of silencing seven An. gambiae genes on P. berghei and P. falciparum infection The effect of reducing expression of the five genes previously reported [12] as well as GSTT1 and GSTT2 in An. gambiae infected with P. falciparum (3D7 strain) was evaluated (Figure 2). Silencing of ArgK and Hsc-3 significantly reduced infection (P < 0.05 and P < 0.001, respectively, using the KS test) (Figure 2A, B). Sol. Trsp., GSTT1, and OXR1 silencing did not affect P. falciparum infection (Figure 2C–E), while tetraspanin and GSTT2 knockdown enhanced infection (P < 0.