Contact : Philippe SILAR
Professor - Principal Team Investigator
Phone : +331 69 15 46 58
Building 400, Room 304
SILAR Philippe, Professor of University of Paris 7 Denis Diderot, HDR
MALAGNAC Fabienne, Lecturer, University of Paris 7 Denis Diderot, HDR
BRUN Sylvain, Lecturer, University of Paris 7 Denis Diderot
LALUCQUE Hervé, Lecturer, University of Paris 7 Denis Diderot
CHAPELAND-LECLERC Florence, Lecturer, University of Paris-Descartes, HDR
RUPRICH-ROBERT Gwenaël, Lecturer, University of Paris-Descartes
TIMPANO Hélène, Post-doc ATER, University of Paris-Sud 11
GROGNET Pierre, Ph. D. Studentt, University of Paris 7 Denis Diderot
XIE Ning, Doctorant, University of Paris 7 Denis Diderot
TANGTHIRASUNUN Narumon, Ph. D. Student, University of Paris7 Denis Diderot / MaeFah Lung University (Thaïlande)
CHAN HO TONG Laetitia, Engineer, ANR
FRANCOIS Sylvie, Technician, University of Paris-Sud 11
BOUILLON Julien, Master Student
IVANOFF Dimitri, Master Student
Genetic and Epigenetic of fungi
Initially centered on cellular degenerative phenomena, our research recently led to a better comprehension of various aspects of fungal biology. We chose as a "model" organism, the filamentous fungus Podospora anserina because this ascomycete is easy to study in the lab. Its complete sexual cycle lasts one week. P. anserina can be grown on well-defined and simple media and last but not least, screening or making mutants in this organism is very easy. These mutants can then be analyzed up to the molecular level thanks to the possibility to transform with DNA P. anserina cells. Recently, we have extended the number of fungal species (coprinus, penicillium, chaetomium…) on which we perform experiments.
Like most fungi P. anserina alternate between a mycelial form and a sporal form:
- The mycelial form is the trophic phase. It possesses all the characteristics of the euascomycete mycelium: apical extension, septation and anastomosis. However, during growth, P. anserina presents two cell degenerative syndromes: Senescence studied for now more than 40 years and Crippled Growth that we discovered in the lab. These two degenerations are under the control of non-conventional genetic elements, which are "cytoplasmic and infectious determinants". Such elements are very widespread in fungi and are not genetic elements (plasmides, virus…) but rather epigenetic elements. Moreover, in nature, P. anserina grows on herbivore dung, where many other fungal species also inhabit. We have shown that P. anserina mycelium presents a defence mechanism to cope with competitors.
- The sporal form is obtained solely after meiosis as ascospores that are used for dissemination. These ascospores are produced in a differentiated structure (the perithecium) during sexual reproduction. The development of perithecia is controlled by numerous factors including starvation and light. Once produced, ascospores are ejected in an active manner outside the perithecium. They do not germinate spontaneously but require a stimulus (the passage through the digestive tractus of an herbivore) that is easily recreated in the lab.
Our goal is to understand how the different steps of P. anserina cycle are regulated. We focus on the roles of the three MAP kinase cascades resent in P. anserina genome because they are required at various moments of the life cycle. Additionaly, we study NADPH oxidases. These enzymes of the plasma membrane generate ROS, which have a role in signalling. We also recently showed that these signalling cascades also regulate the way the fungus degrades plant biomass. Our research thus also focuses on how fungi degrade dead plant materials. More specifically, we seek to understand how cellular differentiations enable mycelia to penetrate their substrate and how they enable to scavenge efficiently nutrients.
Keywords: Cell Degeneration, Epigenetic, Non-conventional Infectiuous Elements, Translation and signal transduction
1- Jamet-Vierny C, Boulay J & Briand JF (1997) Intramolecular cross-overs generate deleted mitochondrial DNA molecules in Podospora anserina. Curr. Genet. 31, 162-170.
2- Jamet-Vierny C, Boulay J, Begel O & Silar P (1997) Contribution of various classes of defective mitochondrial DNA molecules to senescence in Podospora anserina. Curr. Genet. 31, 171-178.
3- Silar P, Koll F & Rossignol M (1997) Cytosolic ribosomal mutations that abolish amplification of circular intron without preventing senescence in Podospora anserina. Genetics 145: 697:705.
4- Gagny B, Rossignol M & Silar P (1997) Cloning, sequencing and transgenic expression of Podospora curvicolla and Sordaria macrospora eEF1A genes: relationship between cytosolic translation and longevity in filamentous fungi. Fung. Genet. Biol. 22: 191-198.
5- Jamet-Vierny C, Contamine V, Boulay J, Zickler D & Picard M (1997) Mutations in genes encoding the mitochondrial outer membrane proteins Tom70 and Mdm10 of Podospora anserina modify the spectrum of mitochondrial DNA rearrangements associated with cellular death. Mol. Cell. Biol, 17, 6359-6366.
6- Gagny B & Silar P (1998) Identification of the genes encoding the cytosolic translation release factors from Podospora anserina and analysis of their role during the life cycle. Genetics 149: 1763-1765.
7- Silar P, Haedens V, Rossignol M & Lalucque H (1999) Propagation of a novel cytoplasmic, infectious and deleterious determinant is controlled by translational accuracy in Podospora anserina. Genetics 151: 87-95.
8- Silar P & Daboussi M.J (1999) Non-conventional infectious elements in filamentous fungi. Trends Genet. 15: 141-145.
9- Jamet-Vierny C, Rossignol M, Haedens V & Silar P (1999) What triggers Senescence in Podospora anserina? Fung. Genet. Biol. 27: 26-35.
10- Silar P, Rossignol M, Haedens V, Derhy Z & Mazabraud A (2000) Deletion & dosage modulation of the eEF1A gene in Podospora anserina : effect on the life cycle. Biogerontology 1: 47-54.
11- Silar P, Rossignol M, Tahar R, Derhy Z & Mazabraud M (2000) Informational suppressor alleles of eEF1A gene, fertility & cell degeneration in Podospora anserina. Mol. Gen. Genet. 264: 354-362.
12- Lalucque H & Silar P (2000) In vivo labelling of functional ribosomes reveals spatial regulation during starvation in Podospora anserina. BMC Genetics 1:3.
13- Silar P, Lalucque H & Vierny C (2001) Cell degeneration in the model system Podospora anserina. Biogerontology 2: 1-17.
14- Silar P, Lalucque H, Haedens V, Zickler D & Picard M (2001) eEF1A controls ascospore differentiation through elevated accuracy, but controls longevity and fruiting body formation through another mechanism in Podospora anserina. Genetics 158: 1477–1489.
15- Barreau C, Sellem C, Silar P, Sainsard-Chanet A & Turcq B (2002) A rapid and efficient method using chromoslots to assign any newly cloned DNA sequence to its cognate chromosome in the filamentous fungus Podospora anserina. FEMS Microbiol. lett. 216: 55-60.
16- Lalucque H & Silar P (2003) NADPH oxidases : an enzyme for multicellularity? Trends Microbiol. 11: 9-12.
17- Silar P, Barreau C, Debuchy R, Kicka S, Turcq B, Sainsard-Chanet A, Sellem CH, Billault A, Cattolico L, Duprat S & Weissenbach J (2003) Characterization of the genomic organization of the region bordering the centromere of chromosome V of Podospora anserina by direct sequencing. Fung. Genet. Biol. 39:250-63.
18- Malagnac F & Silar P (2003) Non-Mendelian determinants of morphology in fungi. Curr. Op. Microbiol. 6:641-645.
19- Lalucque H & Silar P (2004) Incomplete penetrance and variable expressivity of a growth defect as a consequence of knocking out two K+ transporters in the euascomycete fungus Podospora anserina. Genetics 166: 125-134.
20- Kicka S & Silar P (2004) PaASK1, a MAPKKK that controls cell degeneration and cell differentiation in Podospora anserina. Genetics 166: 1241-1252.
21- Graziani S, Silar P & Daboussi M.J (2004) Bistability and hysteresis of the "Secteur" differentiation is controlled by a two-gene locus in Nectria haematococca. BMC Biology 2:18.
22- Malagnac F, Lalucque H, Lepère G & Silar P (2004) Two NADPH oxidase isoforms are required for sexual reproduction and ascospore germination in the filamentous fungus Podospora anserina. Fung. Genet. Biol. 41: 982-997.
23- Silar P (2005) Peroxide accumulation and cell death in filamentous fungi induced by contact with a contestant. Mycol. Res. 109: 137-149.
24- Haedens V, Malagnac F & Silar P (2005) Genetic control of an epigenetic cell degeneration syndrome in Podospora anserina. Fung. Genet. Biol. 42: 564-577.
25- Kicka S, Bonnet C, Sobering A.K, Ganesan L.P & Silar P (2006) A mitotically inheritable unit containing a MAP kinase module. Proc. Natl. Acad. Sci. U.S.A. 36: 13445-13450.
26- Malagnac F & Silar P (2006) Regulation, cell differentiation and protein-based inheritance. Cell Cycle. 5: 2584 - 2587.
27- Dequard-Chablat M & Silar P (2006) Podospora anserina AS6 gene encodes the cytosolic ribosomal protein of the E. coli S12 family. Fung. Genet. Newslett. 53: 26-29.
28- Coppin E & Silar P (2007) Identification of PaPKS1, a polyketide synthase involved in melanin formation and its utilization as a genetic tool in Podospora anserina. Mycol. Res. 111: 901-908.
29- Jamet-Vierny C, Debuchy R, Prigent M & Silar P (2007) IDC1, a Pezizomycotina-specific gene that belongs to the PaMpk1 MAP kinase transduction cascade of the filamentous fungus Podospora anserina. Fung. Genet. Biol. 44: 1219-1230.
30- Malagnac M, Klapholz B & Silar P (2007) PaTrx1 and PaTrx3, two cytosolic thioredoxins of the filamentous ascomycete Podospora anserina involved in sexual development and cell degeneration. Euk. Cell 6: 2323-2331.
31- Espagne E*, Lespinet O*, Malagnac F*, Da Silva C, Jaillon O, Porcel B. M, Couloux A, Aury J.M, Ségurens B, Poulain J, Anthouard V, Grossetete S, Khalili H, Coppin E, Déquard-Chablat M, Picard M, Contamine V, Arnaise S, Bourdais A, Berteaux-Lecellier V, Gautheret D, de Vries R.P, Battaglia E, Coutinho P.M, Danchin E.G.J, Henrissat B, El Khoury R, Sainsard-Chanet A, Boivin A, Pinan-Lucarré B, Sellem C.H, Debuchy R, Wincker P, Weissenbach J.& Silar P (2008) The Genome Sequence of the Model Ascomycete Fungus Podospora anserina Genome Biology 9:R77. * These authors contributed equally to the work.
32- Lambou K, Malagnac F, Barbisan C, Tharreau D, Lebrun MH & Silar P (2008) The crucial role during ascospore germination of the Pls1 tetraspanin in Podospora anserina provides an example of the convergent evolution of morphogenetic processes in fungal plant pathogens and saprobes Euk. Cell 7: 1809-1818.
33- Malagnac F, Bidard F, Lalucque H, Brun S, Lambou K, Lebrun MH & Silar P (2008) Convergent evolution of morphogenetic processes in fungi: Role of tetraspanins and NADPH oxidases 2 in plant pathogens and saprobes. Communicative & Integrative Biology 1:180-181.
34- Martins M, Rodrigues-Lima F, Dairou J, Lamouri A, Malagnac F, Silar P & Dupret JM (2009) An acetyltransferase conferring tolerance to toxic aromatic amine chemicals: molecular and functional studies. J. Biol. Chem. 284: 18726-18733.
35- Brun S, Malagnac F, Bidard F, Lalucque H. and Silar P (2009) Functions and regulation of the Nox family in the filamentous fungus Podospora anserina : a new role in cellulose degradation. Mol. Microbiol. 74: 480-496.
36- Bidard F, Imbeaud S, Reymond N, Lespinet O, Silar P, Clave C, Delacroix H, Berteaux-Lecellier V & Debuchy R (2010) A general framework for optimization of probes for gene expression microarray and its application to the fungus Podospora anserina. BMC Res Notes. 3: 171.
37- Grissa I, Bidard F, Grognet P, Grossetete S & Silar P (2010) The Nox/Ferric reductase/Ferric reductase-like families of Eumycetes. Fungal Biol. 114: 766-777.
38- Martins M, Dairou J, Rodrigues-Lima F, Dupret JM & Silar P (2010) Insights into the phylogeny or arylamine N-acetyltransferases in fungi. J. Mol. Evol. 71:141–152.
39- Espagne E, Vasnier C, Storlazzi A, Kleckner N, Silar P, Zickler D & Malagnac F (2011) Sme4 coiled-coil protein mediates synaptonemal complex assembly, recombinosome relocalization and spindle pole body morphogenesis. Proc. Natl. Acad. Sci. U.S.A. 26: 10614-10619.
40- Silar P (2011) Grafting as a mean to study development in the filamentous fungus Podospora anserina. Fungal Biol. 115- 793-802.
41- Bidard F, Aït Benkhali J, Coppin E, Imbeaud S, Grognet P, Delacroix H & Debuchy R (2011) Genome-wide gene expression profiling of fertilization competent mycelium in opposite mating types in the heterothallic fungus Podospora anserina. PLoS One 6(6): e21476.
42- Bourdais A, Bidard F, Zickler D, Berteaux-Lecellier V, Silar P & Espagne E (2012) Wood utilization is dependent on catalase activities in the filamentous fungus Podospora anserina. PLoS One 7(4): e29820.
43- Lasrama S, Oueslati S, Mliki A, Ghorbel A, Silar P & Chebil S (2012) Ochratoxin A and ochratoxigenic black Aspergillus species in Tunisian grapes cultivated in different geographic areas. Food Control 25: 75-80.
44- Lalucque H, Malagnac F, Brun S, Kicka S & Silar P (2012) A non-mendelian MAPK-generated hereditary unit controlled by a second MAPK pathway in Podospora anserina. Genetics 191: 419–433.
45- Coppin E, Berteaux-Lecellier V, Bidard F, Brun S, Ruprich-Robert G, Espagne E, Aït-Benkhali J, Goarin A, Nesseir A, Planamente S, Debuchy R & Silar P (2012) Systematic deletion of homeobox genes in Podospora anserina uncovers their roles in shaping the fruiting body. PLoS ONE 7(5): e37488.
46- Bidard F, Coppin E & Silar P (2012) The transcriptional response to the inactivation of the PaMpk1 and PaMpk2 MAP kinase pathways in Podospora anserina. Fung. Genet. Biol. 49: 643–652.
47- Grognet P, Lalucque H & Silar P (2012) The PaAlr1 magnesium transporter is required for ascospore development in Podospora anserina. Fung. Biol. 116: 1111-1118.
48- Ropars J, Dupont J, Fontanillas E, Rodríguez de la Vega R, Malagnac F, Coton M, Giraud T, López-Villavicencio M (2012) Sex in cheese: evidence for sexuality in the fungus Penicillium roqueforti. PLOS One (2012) 7(11): e49665.
49- Morcx S, Kunz C, Choquer M, Assié S, Blondet, Simond-côte E, Gajek K, Chapeland-Leclerc F, Expert D, Soulié M-C. (2012) Disruption of Bcchs4, Bcchs6 or Bcchs7 chitin synthase genes in Botrytis cinerea and the essential role of classVI chitin synthase (Bcchs6). Fung. Genet. Biol. sous presse.
1- Debuchy R, Berteaux-Lecellier V & Silar P (2010) Mating Systems and Sexual Morphogenesis in Ascomycetes. In Cellular and Molecular Biology of Filamentous Fungi. K. Borkovich and D. Ebbole eds. pp. 501-535.
2- Brun S & Silar P (2010) Convergent evolution of morphogenetic processes in fungi. In Evolutionary Biology - Concepts, Molecular and Morphological Evolution. pp. 317-328.
3- Lalucque H, Malagnac F & Silar P (2010) Prions and Prion-like Phenomena in Epigenetic Inheritance. In HANDBOOK OF EPIGENETICS. Trygve Tollefsbol ed. pp. 63-76.
4- Malagnac F & Silar P (2010) Epigenetics of Eukaryotic Microbes. In HANDBOOK OF EPIGENETICS. Trygve Tollefsbol ed. pp. 185-201.
5- Cocaign A, Dairou J, Busi F, Silar P, Martins M, Mougin C, Rodrigues-Lima F & Dupret JM (2011) Pesticide-Derived Aromatic Amines and Their Biotransformation. In Pesticide in the Modern World. Margarita Stoytcheva ed. pp 601-614.
6- Silar P (2012) Hyphal Interference: self versus non-self fungal recognition and hyphal death. In Biocommunication of Fungi. Günther Witzany ed. pp 155-170.
1- Silar P, Vierny C, Gagny B, Rossignol M. et Haedens V : Génétique de deux dégénérescences cellulaires chez le champignon filamenteux Podospora anserina. C. R. Soc. Biol. 191: 563-577.
2- Martins M, Silar P, Dairou J, Malagnac F, Rodrigues-Lima F & Dupret JM (2007) Cloning, and functional characterization of two NAT enzymes in the soil fungus Podospora anserina. FEBS J. 274: 226.
3- Silar P, Dairou J, Cocaign A, Busi F, Rodrigues-Lima F & Dupret JM (2011) Fungi as a promising tool for bioremediation of soils contaminated with aromatic amines, a major class of pollutants. Nat. Rev. Microbiol. 9: 477.
Others publications of the lab Members in external collaboration
1- Padilla-Parra S, Audugé N, Lalucque H, Mevel JC, Coppey-Moisan M & Tramier M. (2009) Quantitative comparison of different fluorescent protein couples for fast FRET-FLIM acquisition. Biophys J. 97:2368-76.
2- Storlazzi A, Gargano S, Ruprich-Robert G, Falque M, David M, Kleckner N, Zickler D (2010) Recombination proteins mediate meiotic spatial chromosome organization and pairing. Cell. 2010 141:94-106.
3- Ruprich-Robert G, Thuriaux P (2010) Non-canonical DNA transcription enzymes and the conservation of two-barrel RNA polymerases. Nucleic Acids Res. 2010 38:4559-4569.
4- Chapeland-Leclerc F, Hennequin C, Papon N, Noël T, Girard A, Socié G, Ribaud P, Lacroix C (2010 ) Acquisition of flucytosine, azole, and caspofungin resistance in Candida glabrata bloodstream isolates serially obtained from a hematopoietic stem cell transplant recipient. Antimicrob Agents Chemother. 54:1360-2.
5- Ruprich-Robert G, Wery M, Després D, Boulard Y & Thuriaux P (2011) Crucial role of a dicarboxylic motif in the catalytic center of yeast RNA polymerases. Curr Genet. 57:327-34.