©2018 by Barel Weiner

barelkess.w@gmail.com

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OUR Research

The origin of sex

Sex, the ability of cells to fuse and shuffle genetic material between them (via recombination) is an ancestral trait of eukaryotes, but where did it come from? Like other molecular features of eukaryotes, it probably originates in the archaea. We are studying "prokaryotic sex" - cell fusion and recombination in archaea - using genomics and genetics. This is also a great model system to test the effects of extreme horizontal gene transfer between related and distant microbial species.

Evolutionary roles of CRISPR-Cas systems

CRISPR-Cas systems are microbial defence systems that provide prokaryotes with acquired and heritable DNA-based immunity against selfish genetic elements, primarily viruses. Since CRISPR-Cas systems can impede lateral gene transfer, it is often assumed that they reduce genetic diversity. Conversely, our recent results suggest the exact opposite: namely that these systems generate a high level of genomic diversity within populations. We are studying the eco-evolutionary role of CRISPR-Cas systems in shaping microbial populations, using ecologically-guided genomics and experimental evolution.

The human microbiome in health and disease

The human microbiome has been attracting tremendous interest since there is increasing evidence supporting the involvement of the gut microbes in several human diseases: from inflammatory bowel diseases, colorectal cancer and irritable bowel syndrome to metabolic syndrome and cardiovascular disease. We are studying the microbiome in inflammatory bowel disease (IBD) and test whether personalized bacteria-targeted interventions, either nutritional or probiotic, can support a better microbial community and help extend periods of remission. We are also looking at the emergence of antibiotic resistance in antibiotic-treated IBD and how it affects treatment success.

RNA viruses are the fastest evolving and the simplest self-replicating biological entities. As such they represent excellent models for evolutionary biology, and also can potentially be exploited in phage therapy. We are studying the evolution of RNA coliphage MS2 and are attempting to isolate RNA viruses of archaea from hypersaline ecosystems.

Evolution of prokaryotic RNA viruses