Evolution of insect innate immunity through domestication of bacterial toxins

Toxin cargo genes are often horizontally transferred by phages between bacterial species and are known to play an important role in the evolution of bacterial pathogenesis. Here, we show how these same genes have been horizontally transferred from phage or bacteria to animals and have resulted in novel adaptations. We discovered that two widespread bacterial genes encoding toxins of animal cells, cytolethal distending toxin subunit B ( cdtB ) and apoptosis-inducing protein of 56 kDa ( aip56) , were captured by insect genomes through horizontal gene transfer from bacteria or phages. To study the function of these genes in insects, we focused on Drosophila ananassae as a model. In the D. ananassae subgroup species, cdtB and aip56 are present as singular ( cdtB ) or fused copies ( cdtB::aip56 ) on the second chromosome. We found that cdtB and aip56 genes and encoded proteins were expressed by immune cells, some proteins were localized to the wasp embryo’s serosa, and their expression increased following parasitoid wasp infection. Species of the ananassae subgroup are highly resistant to parasitoid wasps, and we observed that D. ananassae lines carrying null mutations in cdtB and aip56 toxin genes were more susceptible to parasitoids than the wild type. We conclude that toxin cargo genes were captured by these insects millions of years ago and integrated as novel modules into their innate immune system. These modules now represent components of a heretofore undescribed defense response and are important for resistance to parasitoid wasps. Phage or bacterially derived eukaryotic toxin genes serve as macromutations that can spur the instantaneous evolution of novelty in animals

Combined analysis of surface reflection imaging and vertical seismic profiling at Yucca Mountain, Nevada

This report presents results from surface and borehole seismic profiling performed by the Lawrence Berkeley Laboratory (LBL) on Yucca Mountain. This work was performed as part of the site characterization effort for the potential high-level nuclear waste repository. Their objective was to provide seismic imaging from the near surface (200 to 300 ft. depth) to the repository horizon and below, if possible. Among the issues addressed by this seismic imaging work are location and depth of fracturing and faulting, geologic identification of reflecting horizons, and spatial continuity of reflecting horizons. The authors believe their results are generally positive, with tome specific successes. This was the first attempt at this scale using modem seismic imaging techniques to determine geologic features on Yucca Mountain. The principle purpose of this report is to present the interpretation of the seismic reflection section in a geologic context. Three surface reflection profiles were acquired and processed as part of this study. Because of environmental concerns, all three lines were on preexisting roads. Line 1 crossed the mapped surface trace of the Ghost Dance fault and it was intended to study the dip and depth extent of the fault system. Line 2 was acquired along Drill Hole wash and was intended to help the ESF north ramp design activities. Line 3 was acquired along Yucca Crest and was designed to image geologic horizons which were thought to be less faulted along the ridge. Unfortunately, line 3 proved to have poor data quality, in part because of winds, poor field conditions and limited time. Their processing and interpretation efforts were focused on lines 1 and 2 and their associated VSP studies

Horizontal Transfer of Bacterial Cytolethal Distending Toxin B Genes to Insects

Horizontal gene transfer events have played a major role in the evolution of microbial species, but their importance in animals is less clear. Here, we report horizontal gene transfer of cytolethal distending toxin B (cdtB), prokaryotic genes encoding eukaryote-targeting DNase I toxins, into the genomes of vinegar flies (Diptera: Drosophilidae) and aphids (Hemiptera: Aphididae). We found insect-encoded cdtB genes are most closely related to orthologs from bacteriophage that infect Candidatus Hamiltonella defensa, a bacterial mutualistic symbiont of aphids that confers resistance to parasitoid wasps. In drosophilids, cdtB orthologs are highly expressed during the parasitoid-prone larval stage and encode a protein with ancestral DNase activity. We show that cdtB has been domesticated by diverse insects and hypothesize that it functions in defense against their natural enemies

Evolution of insect innate immunity through domestication of bacterial toxins

Toxin cargo genes are often horizontally transferred by phages between bacterial species and are known to play an important role in the evolution of bacterial pathogenesis. Here, we show how these same genes have been horizontally transferred from phage or bacteria to animals and have resulted in novel adaptations. We discovered that two widespread bacterial genes encoding toxins of animal cells, cytolethal distending toxin subunit B (cdtB) and apoptosis-inducing protein of 56 kDa (aip56), were captured by insect genomes through horizontal gene transfer from bacteria or phages. To study the function of these genes in insects, we focused on Drosophila ananassae as a model. In the D. ananassae subgroup species, cdtB and aip56 are present as singular (cdtB) or fused copies (cdtB::aip56) on the second chromosome. We found that cdtB and aip56 genes and encoded proteins were expressed by immune cells, some proteins were localized to the wasp embryo's serosa, and their expression increased following parasitoid wasp infection. Species of the ananassae subgroup are highly resistant to parasitoid wasps, and we observed that D. ananassae lines carrying null mutations in cdtB and aip56 toxin genes were more susceptible to parasitoids than the wild type. We conclude that toxin cargo genes were captured by these insects millions of years ago and integrated as novel modules into their innate immune system. These modules now represent components of a heretofore undescribed defense response and are important for resistance to parasitoid wasps. Phage or bacterially derived eukaryotic toxin genes serve as macromutations that can spur the instantaneous evolution of novelty in animals

Genital powder use and risk of ovarian cancer: a pooled analysis of 8,525 cases and 9,859 controls

Martin K. Oehler is a member of the Australian Ovarian Cancer Study GroupAbstract not availableKathryn L. Terry, Stalo Karageorgi, Yurii B. Shvetsov, Melissa A. Merritt, Galina Lurie, Pamela J. Thompson, Michael E. Carney, Rachel Palmieri Weber, Lucy Akushevich, Wei-Hsuan Lo-Ciganic, Kara Cushing-Haugen, Weiva Sieh, Kirsten Moysich, Jennifer A. Doherty, Christina M. Nagle, Andrew Berchuck, Celeste L. Pearce, Malcolm Pike, Roberta B. Ness, Penelope M. Webb, for the Australian Cancer Study, Ovarian Cancer, and the Australian Ovarian Cancer Study Group, Mary Anne Rossing, Joellen Schildkraut, Harvey Risch, and Marc T. Goodman, on behalf of the Ovarian Cancer Association Consortiu

Use of talcum powder and endometrial cancer risk

Purpose: Use of talcum powder in the perineal area has been associated with an increased risk of ovarian cancer, and a recent cohort study found a positive association with endometrial cancer. We sought to confirm this association using data from the Australian National Endometrial Cancer Study (ANECS). Methods: ANECS was a population-based case-control study conducted from 2005 to 2007, in which 1,399 women with newly diagnosed histologically confirmed primary endometrial cancer and 740 control women provided risk factor information via telephone interview. Unconditional logistic regression was used to estimate odds ratios adjusting for potential confounders. Results: We found no significant association between ever use of talc in the perineal area (OR 0.88, 95% CI: 0.68-1.14) or upper body area (OR 0.90, 95% CI: 0.71-1.14) and risk of endometrial cancer. The results were similar when stratified by subtype. Composite variables combining frequency and duration of talc use were also not significantly associated with risk (any perineal area use p = 0.07 and any upper body use p = 0.49). Conclusions: The absence of any increase in risk and the similarity of our results for talc use on the upper body and in the perineal area do not support the hypothesis that use of talc in the perineal area is associated with an increased risk of endometrial cancer. Our data do not confirm the positive association between perineal talc use and endometrial cancer observed in the only previous study