Figure 1.
Phylogenetic Comparison of Lb17 and Lh14 to Other Characterized Strains
Parsimony trees with bootstrap scores (circled) made from ribosomal RNA ITS2 sequences show the close relationship between (A) Lb17 and (B) Lh14 with other strains of these species [37].
Figure 2.
TEM micrograph of the rounded, vesicle-filled VLPs from the lumen of the long gland reservoir of Lb17 shows that Lb17 VLPs are similar to those from other virulent L. boulardi strains [46].
Figure 3.
Infectivity of Lb17 and Lh14 on Multiple Drosophila Species
Percentage of fly larvae that were successfully parasitized by the wasps (i.e., the percentage of fly larvae from which a wasp eventually hatched). Asterisks indicate that a significant proportion (>5%) of the fly larvae melanotically encapsulated wasp eggs or larvae. The Drosophila phylogeny is a consensus of multiple studies [73,113]; branch lengths are approximate.
Figure 4.
Melanotic Encapsulation of Lb17 Eggs by D. yakuba
(A, C) White light pictures of melanized wasp eggs dissected from D. yakuba larvae. (B, D) Fluorescence pictures of the same melanized wasp eggs. (B) Hoechst nuclear stain—note abundance of cells encapsulating melanized egg. (D) Rhodamine-phalloidin actin cytoskeleton stain—note that encapsulating cells have flattened (lamellocyte) morphology.
Figure 5.
Different Phenotypic Effects of Lb17 and Lh14 Venom
(A) Percentage of Drosophila lamellocytes lysed (bipolar) after incubation with wasp venom in vitro (means and standard errors shown). (B) hopTum-l larvae form melanotic tumors (black arrows), even when infected with either Lb17 (C, E, F) or Lh14 (D, G, H). Though dominant larvae of neither wasp species are encapsulated (white arrows), melanization of supernumerary wasp larvae (white arrowheads) occurs only in Lb17 attacked Drosophila.
Table 1.
Number of Differentially Regulated Drosophila Genes after Wasp Attack for Given t-Test p-Value Cutoffs
Figure 6.
Regulatory Changes in Canonical Immune Pathways after Lb17 Attack
Genes in red are significantly overexpressed and in blue underexpressed by Lb17 attacked flies in at least one of three treatment comparisons (Lb17 versus control, Lb17 + Lh14 versus control, or Lb17 versus Lh14) at one of the two early time points post infection (2–5 or 9–12 h). Dashed arrows represent presumed pathway interactions. Horizontal lines represent cell and nuclear membranes; genes inside the nucleus are targets of the upstream pathway. The main Toll pathway AMP Drosomycin was more than 4-fold up-regulated after Lb17 attack, but this change was not significant due to high variance among control replicates. Of the 33 overexpressed genes represented in this figure, only two, PGRP-SA and PGRP-SD, were also overexpressed in the Lh14 versus control comparison (relative to 21 in the Lb17 versus control comparison).
Figure 7.
Confirmation of Microarray Results at the Protein Level
(A) PO enzyme activity (standardized by total protein levels) in Drosophila larvae 24 h after wasp attack. Means and upper/lower 95% confidence intervals are represented by horizontal lines. (B) Fat body expression of Drosomycin-GFP 24 h after wasp attack.
Table 2.
Percent of Fat Body Cells Fluorescing in the Drosomycin-GFP Strain 5 h after Wasp Attack