Some of our research focuses on the Arbuscular Mycorrhizal Fungi (AMF). These organisms represent an ecologically relevant group of "ancient asexuals" that form important symbioses with the roots of most land plants. This AM symbiosis improves plant's uptake of nutrients from the soil, and results in a higher fitness for the host and ecosystem biodiversity. For this reason, AMF are commonly used in organic practices - i.e. organic farming, plant nurseries) and phytoremediation programs.
In addition to their ecological relevance, AMF are also harbor unique from cellular traits. Specifically, in each AMF cell thousands of nuclei co-exist in one large cytoplasm - i.e. syncitium - and the genome organization of this atypical genetic system has been poorly understood. Our lab has recently made breakthroughs in this area of research, by demonstrating that AMF genetics follow mendelian-like genetics, and that genetic variability in this lineage is most likely triggered by conventional mating processes.
Ultimately, these findings will open avenues for the production of AMF strains tailored for optimized plant growth. To reach this goal, our team continues to identify the molecular and genetic mechanism involved in partner recognition in this fungal group.
- Discovery of extensive genome plasticity in a model AMF: Chen et al. 2018, New Phytologist
- Single cell procedures to expose the genetics of obscure AMF lineages: Beaudet et al. 2018, DNA Research
- For a review on AMF genetics: Corradi and Brachmann 2017, Trends in Plant Science
- First evidence of a mating-type locus and inter-isolate hybridization in AMF: Ropars et al 2016, Nature Microbiology
Microsporidian Parasites and Allies
Our lab also specializes in the analysis of a ubiquitous group of obligate intracellular parasites, called Microsporidia. These organisms infect virtually all animals, including humans,and many species of economic importance, such as salmon, honeybees or the silkworm. In humans, microsporidiosis -i.e. the disease associated with microsporidia infections - is usually benign, but it can lead to severe symptoms such as chronic diarrhoea and encephalitis; in immuno-compromised patients.
The are obligate intracellular parasites, and this is reflected in the size and content of their genomes. Specifically, these are almost always gene poor and, in some cases, extremely small and compact - i.e. the smallest known is only 2.3Mb! Our lab has been involved in genome sequencing projects of many species in this group, as a mean to better understand their biology. Our research resulted in the first population genomic analysis of microsporidians (Pelin et al. 2015, Environmental Microbiology), and are now developing experimental population analyses of these parasites. In this area, our research focuses mainly on species of veterinary (Encephalitozoon sp., a common vertebrate pathogen), scientific (Pseudoloma neurophila; a pathogen of the model Zebrafish) and economic importance (Nosema ceranae, a relevant honeybee parasite).
More recently, the microsporidian Nosema ceranae has hit the spotlight for being associated with global declines in honeybee populations. Our lab has revealed that this parasite has spread globally through human intervention, most likely via international commerce of beehives. We also showed that the N. ceranae genome is polyploidy, an atypical genome organization that increases genetic diversity in global populations of this parasite.
- For a review on microsporidian genomics and evolution: Corradi N. 2015. Annual Review of Microbiology
- Detection of atypical nuclear complexity and dispersion patterns in pathogens of honey-bees: Pelin A. et. al. 2015. Environmental Microbiology.
- Discovery of unusual gene-acquisitions in vertebrate parasites: Selman M. et al. 2011. Current Biology.