Analysis of regulatory protease sequences identified through bioinformatic data mining of the Schistosoma mansoni genome

<p>Abstract</p> <p>Background</p> <p>New chemotherapeutic agents against <it>Schistosoma mansoni</it>, an etiological agent of human schistosomiasis, are a priority due to the emerging drug resistance and the inability of current drug treatments to prevent reinfection. Proteases have been under scrutiny as targets of immunological or chemotherapeutic anti-<it>Schistosoma </it>agents because of their vital role in many stages of the parasitic life cycle. Function has been established for only a handful of identified <it>S. mansoni </it>proteases, and the vast majority of these are the digestive proteases; very few of the conserved classes of regulatory proteases have been identified from <it>Schistosoma </it>species, despite their vital role in numerous cellular processes. To that end, we identified protease protein coding genes from the <it>S. mansoni </it>genome project and EST library.</p> <p>Results</p> <p>We identified 255 protease sequences from five catalytic classes using predicted proteins of the <it>S. mansoni </it>genome. The vast majority of these show significant similarity to proteins in KEGG and the Conserved Domain Database. Proteases include calpains, caspases, cytosolic and mitochondrial signal peptidases, proteases that interact with ubiquitin and ubiquitin-like molecules, and proteases that perform regulated intramembrane proteolysis. Comparative analysis of classes of important regulatory proteases find conserved active site domains, and where appropriate, signal peptides and transmembrane helices. Phylogenetic analysis provides support for inferring functional divergence among regulatory aspartic, cysteine, and serine proteases.</p> <p>Conclusion</p> <p>Numerous proteases are identified for the first time in <it>S. mansoni</it>. We characterized important regulatory proteases and focus analysis on these proteases to complement the growing knowledge base of digestive proteases. This work provides a foundation for expanding knowledge of proteases in <it>Schistosoma </it>species and examining their diverse function and potential as targets for new chemotherapies.</p

Critical Comments: Parasitology Year 2000

We predict that in order for parasitology to thrive by the year 2000 the various subdisciplines of evolution, ecology, biosystematics, and genetics must develop holistic approaches and use parasite models to answer basic biological questions. The students of tomorrow must work as part of a multidisciplinary team; and their questions and answers must be conceptually integrated into the broader biological framework of evolution and ecology

Statistics Information for each Dependent variable

This is a table containing specific statistical output for each dependent variable

Data from: One stimulus - two responses: host and parasite life history variation in response to environmental stress

Climate change stressors will place different selective pressures on both parasites and their hosts, forcing individuals to modify their life history strategies and altering the distribution and prevalence of disease. Few studies have investigated whether parasites are able to respond to host stress and respond by varying their reproductive schedules. Additionally, multiple environmental stressors can limit the ability of a host to respond adaptively to parasite infection. This study compared both host and parasite life history parameters in unstressed and drought-stressed environments using the human parasite, Schistosoma mansoni in its freshwater snail intermediate host. Snail hosts infected with the parasite demonstrated a significant reproductive burst during the pre-patent period (fecundity compensation), but that response was absent in a drought-stressed environment. This is the first report of the elimination of host fecundity compensation to parasitism when exposed to additional environmental stress. More surprisingly, we found that infections in drought-stressed snails had significantly higher parasite reproductive outputs than infections in unstressed snails. The finding suggests that climate change may alter the infection dynamics of this human parasite

Additional file 1: Tables S1-S26 and Figures S1-S16. of The influence of trematode parasite burden on gene expression in a mammalian host

Contains additional results, primer sequences, RNA quality parameters, descriptive statistics and annotation details of assemblies, GO terms (lists and figures), significantly enriched KEGG IDs, xenobiotic characterizations, PCR results and qPCR validations. (PDF 2247 kb

Downstream effects: Impact of antibiotic pollution on an aquatic host–parasite interaction

Abstract The global increase in antibiotic use has led to contamination of freshwater environments. Despite the identified impacts of antibiotics on humans and wildlife, the effect of antibiotics on host–parasite life cycles in freshwater is relatively unexplored. In the current study, we utilize the trematode parasite Schistosoma mansoni, and its snail intermediate host, Biomphalaria glabrata, to investigate the influence of an ecologically relevant antibiotic concentration on the life history characteristics of both parasite and host. Our results demonstrate that antibiotics not only accelerate parasite development time, but also increase host reproduction and delay parasite‐induced host castration. Using a mathematical model, we suggest that life history alterations associated with antibiotics are likely to increase parasite transmission and disease burden. Our study suggests that antibiotic pollution could impact freshwater ecosystems by influencing host–parasite dynamics and potentially increase the burden of schistosomiasis in endemic regions