Figure 1.
Effect of cell ablation on P. pacificus.
Z2 and Z3 give rise germline and Z1 and Z4 give rise to somatic gonad (A). P. pacificus WT un-ablated (B). P. pacificus WT stained with Oil red O showing tryglyceride staining of intestine, hypodermis, gonad and eggs (C) and P. pacificus Z2 and Z3 and ablated similarly stained showing concentration of triglycerides in intestine, like germline ablated C. elegans (46) (D). Scale bar represents approx. 100 µm.
Figure 2.
Effect of ablation of survival of P. pacificus fed bacterial pathogens.
Number of alive P. pacificus WT (blue), Z2 and Z3 ablated (red) and Z1 and Z4 (yellow) exposed to S. marcescens (A) and X. nematophila (B). Batches consisting of twenty nematodes were added separately to three plates and survival was monitored daily beginning on day 0. Error bars represent ± S.E.M.
Figure 3.
Effect of ablation of survival of Pristionchus species and strains exposed to S. marcescens.
Survival of (A) P. pacificus S264 Z2 and Z3 ablated (red) and un-ablated (blue), (B) P. pacificus M2 Z2 and Z3 ablated (red) and un-ablated (blue), (C) P. pacificus RS5160 Z2 and Z3 ablated (red) and un-ablated (blue), (D) Pristionchus sp. 3 Z2 and Z3 ablated (red) and un-ablated (blue), (E) Pristionchus sp. 16 Z2 and Z3 ablated (red) and un-ablated (blue). Error bars represent ± S.E.M.
Figure 4.
Enhanced longevity due to germline ablation is the major transcriptional component of increased pathogen resistance of these animals.
In this schematic of microarrays comparisons, each experiment is represented by two parameters - the ablation status and the bacteria fed, while the double arrows show the samples co-hybridized on the same array. In the first experiment E1, 3,335 genes were differentially expressed when germline ablated animals fed on E. coli were compared against un-ablated animals also fed on E. coli. In second experiment, E2, only 244 genes were differentially expressed when ablated animals exposed to S. marcescens were compared against ablated animals exposed only to E. coli, thus indicating that effects of germline ablation are the major transcriptional component towards increased lifespan and pathogen resistance. We also compared these data to transcriptional response of wild-type P. pacificus worms exposed to S. marcescens (experiment E3, 552 genes, AS, RR, II and RJS, unpublished data). Using these data, we calculated the comparison E4 between ablated versus unablated animals, both fed on S. marcescens, and found 2,962 differentially expressed genes.
Table 1.
Microarray expression clusters showing significant overlap with genes up or down regulated upon germline ablation in P. pacificus.
Figure 5.
Effect of Z2 and Z3 germline ablation on survival of P. pacificus insulin signaling mutants exposed to S. marcescens.
Survival of Z2 and Z3 ablated P. pacificus WT (red), Ppa-daf-16 (tu901) (orange), Ppa-daf-16 (tu302) (green), Ppa-daf-12 (tu390) (blue) and Ppa-daf-12 (tu389) (yellow). Error bars represent ± S.E.M.