Molecular Genetics Project

Arbuscular mycorrhizal fungi (AMF) are presumed to be asexual organisms that reproduce via large multinucleated spores. Sexual reproduction has never been observed in AMF.
The goal of this research project is to investigate the potential sexual reproduction and the genome structure of AMF using next-generation sequencing and comparative genomics, and to define the extent of genetic variation in AMF with a particular focus on the way polymorphism is maintained and lost by processes such as mutation, recombination, anastomosis and genetic drift. Using a high-throughput genomic, bioinformatic and cellular imaging approaches, we will improve our understanding of processes that govern this major eukaryotic symbiosis.


Short-term aims are: (i) To screen for genes involved in sexual reproduction in AMF using genome sequencing libraries available in our lab; (ii) To test in AMF systems various pheromones (and their precursos) known to be involved in the regulation of mating reactions in Zygomycetes, such as trisporic acid; and to follow the expression of key genes involved in sexual reproduction and morphology changes using cellular imaging approach; (iii) To study gene exchange between genetically different individuals using crossing experiments and genotyping with mitochondrial DNA markers, and studying exchanges at anastomoses. This research will generate novel and significant knowledge on AMF biology, genetics and genomics. It will also yield fundamental insights into the reproduction of fungi. Studying the basis for the persistence of multiple genomes in AMF will expand our knowledge of the genomics of symbiotic organisms. Furthermore, it will advance our understanding of genome-genome interactions.

Spores of our model glomeromycete species Glomus irregulare isolate DAOM-197198. (J. Marleau).

Glomus irregulare spore (SEM)

Crossing between two individuals

Example of a crossing experiment between two individuals of Glomus irregulare in vitro on transformed carrot roots.

Anastomosis between two individuals

Anastomosis between two geneticaly divergent individuals of G. irregulare. After hyphal fusion, cytoplasms of the two individuals are mixed and a bidirectional streaming occurs.

This project is funded by:

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