Open AccessComparative Genomic Analysis of Drechmeria coniospora Reveals Core and Specific Genetic Requirements for Fungal Endoparasitism of Nematodes
Author(s) -
Kévin Lebrigand,
Le He,
Nishant Thakur,
Marie-Jeanne Arguel,
Jolanta Polanowska,
Bernard Henrissat,
Éric Record,
Ghislaine Magdelenat,
Valérie Barbe,
Sylvain Raffaele,
Pascal Barbry,
Jonathan J. Ewbank
Publication year - 2016
Publication title -
plos genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.587
H-Index - 233
eISSN - 1553-7404
pISSN - 1553-7390
DOI - 10.1371/journal.pgen.1006017
Subject(s) - biology , obligate , genetics , gene , virulence , genome , obligate parasite , nematode , microbiology and biotechnology , host (biology) , botany , ecology
Drechmeria coniospora is an obligate fungal pathogen that infects nematodes via the adhesion of specialized spores to the host cuticle. D . coniospora is frequently found associated with Caenorhabditis elegans in environmental samples. It is used in the study of the nematode’s response to fungal infection. Full understanding of this bi-partite interaction requires knowledge of the pathogen’s genome, analysis of its gene expression program and a capacity for genetic engineering. The acquisition of all three is reported here. A phylogenetic analysis placed D . coniospora close to the truffle parasite Tolypocladium ophioglossoides , and Hirsutella minnesotensis , another nematophagous fungus. Ascomycete nematopathogenicity is polyphyletic; D . coniospora represents a branch that has not been molecularly characterized. A detailed in silico functional analysis, comparing D . coniospora to 11 fungal species, revealed genes and gene families potentially involved in virulence and showed it to be a highly specialized pathogen. A targeted comparison with nematophagous fungi highlighted D . coniospora -specific genes and a core set of genes associated with nematode parasitism. A comparative gene expression analysis of samples from fungal spores and mycelia, and infected C . elegans , gave a molecular view of the different stages of the D . coniospora lifecycle. Transformation of D . coniospora allowed targeted gene knock-out and the production of fungus that expresses fluorescent reporter genes. It also permitted the initial characterisation of a potential fungal counter-defensive strategy, involving interference with a host antimicrobial mechanism. This high-quality annotated genome for D . coniospora gives insights into the evolution and virulence of nematode-destroying fungi. Coupled with genetic transformation, it opens the way for molecular dissection of D . coniospora physiology, and will allow both sides of the interaction between D . coniospora and C . elegans , as well as the evolutionary arms race that exists between pathogen and host, to be studied.