Category Archives: basidiomycota

2012 Fungal Genomes: a review of mycological genomic accomplishments

2012 was certainly a banner year in genome sequence production and publications. The cost of generating the data keeps dropping and the automation for assembly and annotation continues to improve making it possible for a range of groups to publish genomes.

I made a NCBI PubMed Collection of these here Fungal Genomes 2012

Some notable fungal genome publications include

There were also several new insights into the evolution of wood decay fungi derived from new genomes of basidiomycete fungi. This includes

(Now I might have missed a few in my attempt to get this done before holidays overtake me – if so, please post comments or tweets and I’ll be sure to amend the list on pubmed and here.)

A new trend for fungal genome papers can be seen now in the Genome Announcements of Eukaryotic Cell which aim to get the genome data out quickly with a citateable reference. These are short descriptions which I expect will become more popular ways to insure data made public can also be cited. I only counted about 5 published in 2012 but I expect to see a lot more of these in the 2013 either at EC or other journals. I’m sure there will still be some tension between providers making data public as soon as possible and the sponsoring authors’ desire to have first crack at analyzing and publish interpretations and comparison of the genome(s). The bacterial community has been doing this for Genome Reports in the SIGS journal and the Journal of Bacteriology so will see what happens as these small eukaryotic genomes become even easier to produce.

I look forward to exciting year with more of the 1000 Fungal genomes and other JGI  projects start to roll out more genomes.  I also predict there will be many more resequencing datasets published as functional and population genomics. It will also probably be a countdown for what are the last Sanger sequenced genomes and how the many flavors of next generation sequencing will be optimized for generation.  I am hopeful work on automation of annotation and comparisons will be even easier for more people to use and that we start to provide a shared repository of gene predictions.  I’ve just launched the latter and look forward to engaging more people to contribute to this.

The Alaskan Goo demystified

Another delightful well written piece by Jennifer Frazer in her SciAm blog. She presents a solution to a unknown fungus that showed up as a blanket of orange spores in the water near the town of Kivalina, Alaska. “Mystery of Alaskan “Goo” Rust Solved at Last”. Jennifer writes that the rust spores are from:

Spruce-Labrador Tea Needle RustChrysomyxa ledicola, a parasite of both spruce trees and arhododendron — a flowering woody shrub common to conifer understories the world over — called Labrador Tea.

 

Schizophyllum genome update

Robin Ohm at the JGI has announced the release of version 2 of the Schizophyllum commune genome. This is great news on the heels of the announcement that one of the funded 2012 CSPs will include detailed functional genomics experiments in this mushroom.

I am pleased to announce the public release of the JGI annotation and portal for the improved assembly of Schizophyllum commune.  Annotations of the assembly are now publicly visible at http://jgi.doe.gov/Scommune2 .  Annotation and editing privileges remain password-protected but all other tools are now available to the general public.

A detailed set of statistics on the assembly and annotation can be found on the Info page of that portal:  http://genome.jgi-psf.org/Schco2/Schco2.info.html

 

Myco-bio-diesel

Previously I posted on an article on making biodiesel using the fungus Gliocladium roseum. Here is a new study reporting conversion of lipids to biodiesel using the basidiomycete Cryptococcus curvatus. There has been also other progress in this area where Mucor circinelloides can also be used to produce oils suitable for biodiesel production as reported in the paper and the press release - though it is a pathogenic fungus with interesting spore size dimorphism.

Thiru M, Sankh S, & Rangaswamy V (2011). Process for biodiesel production from Cryptococcus curvatus. Bioresource technology PMID: 21930373

Orange goo is in fact rust spores in Alaska waters

Previously incorrectly identified as eggs, the ‘orange goo’ floating off the shore of a small Alaskan village has now been identified as a rust fungus.

If they had known that a hoard of Mycologists were descending on Alaska for our annual meeting!  I guess the exact identification is still being determined by NOAA labs – hope they can PCR ITS up and figure it out (and maybe save a culture for deposition somewhere).

(Thanks to Blake Billmyre for passing along the story)

Genome sequence of mushroom Schizophyllum commune

Schizophyllum CommuneI am excited to announce the publication of another mushroom genome this week. The mushroom Schizophyllum commune is an important model system for mushroom biology, development of genome was sequenced as part of efforts at the Joint Genome Institute and a collection of international researchers.  The data and analyses from these efforts are presented in a publication appearing in Nature Biotechnology today.

Studies in mushrooms can have important impact on other research areas.  They can be useful in biotechnology as protein biosynthesis factories for producing compounds or even as an edible delivery mechanism for new drugs.  What we found in the analysis of this genome include clues to mechanisms of how white rotting fungi degrade lignin through analysis of enzyme families.  We also saw evidence for extensive antisense transcription during different developmental stages suggesting some important clues as to how some gene regulation could impact or control developmental progression.  Through gene expression comparison (by MPSS) a large number of transcription factors were shown to be differentially regulated during sexual development.  A knockout out two of these (fst3 and fst4) resulting in changes in ability to form mushrooms (fst4) or smaller mushrooms (fst3).

Several more interesting findings in this work that I hope to add back to this post when there is a little more time -

Ohm, R., de Jong, J., Lugones, L., Aerts, A., Kothe, E., Stajich, J., de Vries, R., Record, E., Levasseur, A., Baker, S., Bartholomew, K., Coutinho, P., Erdmann, S., Fowler, T., Gathman, A., Lombard, V., Henrissat, B., Knabe, N., Kües, U., Lilly, W., Lindquist, E., Lucas, S., Magnuson, J., Piumi, F., Raudaskoski, M., Salamov, A., Schmutz, J., Schwarze, F., vanKuyk, P., Horton, J., Grigoriev, I., & Wösten, H. (2010). Genome sequence of the model mushroom Schizophyllum commune Nature Biotechnology DOI: 10.1038/nbt.1643

A mushroom on the cover

I’ll indulge a bit here to happily to point to the cover of this week’s PNAS with an image of Coprinopsis cinerea mushrooms fruiting referring to our article on the genome sequence of this important model fungus.  You should also enjoy the commentary article from John Taylor and Chris Ellison that provides a summary of some of the high points in the paper.

Coprinopsis cover

Stajich, J., Wilke, S., Ahren, D., Au, C., Birren, B., Borodovsky, M., Burns, C., Canback, B., Casselton, L., Cheng, C., Deng, J., Dietrich, F., Fargo, D., Farman, M., Gathman, A., Goldberg, J., Guigo, R., Hoegger, P., Hooker, J., Huggins, A., James, T., Kamada, T., Kilaru, S., Kodira, C., Kues, U., Kupfer, D., Kwan, H., Lomsadze, A., Li, W., Lilly, W., Ma, L., Mackey, A., Manning, G., Martin, F., Muraguchi, H., Natvig, D., Palmerini, H., Ramesh, M., Rehmeyer, C., Roe, B., Shenoy, N., Stanke, M., Ter-Hovhannisyan, V., Tunlid, A., Velagapudi, R., Vision, T., Zeng, Q., Zolan, M., & Pukkila, P. (2010). Insights into evolution of multicellular fungi from the assembled chromosomes of the mushroom Coprinopsis cinerea (Coprinus cinereus) Proceedings of the National Academy of Sciences, 107 (26), 11889-11894 DOI: 10.1073/pnas.1003391107

An Inky-cap mushroom genome

Francis Martin has written up a delightful summary pointing to our publication of the genome of Coprinopsis cinereus which appears in the early edition of PNAS and will grace the cover at the end of the month.  I encourage you to take a look at Francis’s post and the paper, available as Open Access from PNAS.  I’ll do my best to post a summary of the paper when I get a free moment.

For now I’ll leave you with a picture of this cute little mushroom fruting in the lab and a link to many more at Flickr.

Mature Coprinus cinereus (Coprinopsis cinerea)

I’ll have the truffles and huitlacoche

Black TruffleA couple of papers should have captured your attention lately in the realm of fungal genomics.

One is the publication of the genome of the black truffle Tuber melanosporum. This appears as an advanced publication at Nature (OA by virtue of Nature’s agreement on genome papers) along with a NYT writeup and is a tasty exploration of the genome of an ascomycete ectomycorrhizal (ECM) fungus. There are several gems in there including the differences in transposable element content, content of gene families related to carbohydrate metabolism. This genome helps open the doorway for exploring the several independent origins of ECM in both ascomycete and basidiomycete fungi.

I’ll also point out there is some work on the analysis of mating type locus found in this genome has applied aspects suggesting that inoculation of roots with both mating types may increase truffle yields in truffle farms. Evidence for sexual reproduction is also discovered from this genome analysis based on the sexual cycle genes present and the structure of the MAT locus.  Much like what was revealed in the genome analysis of the previously ‘asexual’ species Aspergillus fumigatus (and later reconstitution of a sexual cycle), the Tuber genome has the potential for mating and is a heterothallic (outcrossing) fungus based on its mating type locus -just like many other filamentous Ascomycete species.

A second paper I encourage you take a look at (those with a Science subscription) is from Virginia Walbot’s lab on the formation of tumors by U. maydis in Maize. These tumors end up destroying the corn but can produce a delicious (to some) dish that is huitlacooche. The idea that the fungus is co-opting the host system by secreting proteins that acted in the same way as native proteins and that it has a tissue or organ specific repertoire was one that her lab has been pursuing. U. maydis can grow inside corn without detection and  the formation of tumors seems to be a manipulation of the plant as much as it is the pathogen directly taking resources from the plant.  It reminds me a bit of the production of secondary metabolites that can control plant growth like gibberellins produced by fungi.  This kind of manipulation and also ability to evade detection suggests a pretty specific set of controls that prevent the fungus from doing the wrong thing at the wrong time (to avoid detection). So they set out to see if there are a set of organ specific genes that the fungus uses during infection that would suggest a very host-specific strategy by this corn smut.

In this paper the authors evaluate the role of fungal genes specifically expressed in infection of different organs and also the role of secreted proteins in colonization of the organs.  In what is impressive and elegant work, the authors show through the use of microarrays and genetics that there is plant tissue specific gene expression of U. maydis – so infections in leaves express a different set of genes than those in seedlings.  Genetic and phenotypic evaluation of fungal strains with knockouts of sets of the predicted secreted proteins was able to confirm a role for specific secreted proteins that previously may have not had any discernible phenotype. They infect strains with knockouts of sets of genes that encode secreted proteins and compare the virulence when these strains infect individual organs of the maize host.  They showed there is significantly different virulence in the various tissues for a some of the mutants suggesting an organ-specific role for virulence of secreted proteins. They also go on to show that some of this organ specific infection requires organ-specific gene expression by evaluating maize mutants and the ability of the fungus to infect different organs.

Future work will hopefully followup to see what these secreted proteins are manipulating in the host and how they either enable virulence by protecting the pathogen, avoiding detection by turning of host responses, or co-opting host gene networks in some other way.

Martin F, Kohler A, Murat C, Balestrini R, Coutinho PM, Jaillon O, Montanini B, Morin E, Noel B, Percudani R, Porcel B, Rubini A, Amicucci A, Amselem J, Anthouard V, Arcioni S, Artiguenave F, Aury JM, Ballario P, Bolchi A, Brenna A, Brun A, Buée M, Cantarel B, Chevalier G, Couloux A, Da Silva C, Denoeud F, Duplessis S, Ghignone S, Hilselberger B, Iotti M, Marçais B, Mello A, Miranda M, Pacioni G, Quesneville H, Riccioni C, Ruotolo R, Splivallo R, Stocchi V, Tisserant E, Viscomi AR, Zambonelli A, Zampieri E, Henrissat B, Lebrun MH, Paolocci F, Bonfante P, Ottonello S, & Wincker P (2010). Périgord black truffle genome uncovers evolutionary origins and mechanisms of symbiosis. Nature PMID: 20348908

Skibbe DS, Doehlemann G, Fernandes J, & Walbot V (2010). Maize tumors caused by Ustilago maydis require organ-specific genes in host and pathogen. Science (New York, N.Y.), 328 (5974), 89-92 PMID: 20360107