Category Archives: pezizomycota

Postdoc: Uppsala University on Meiotic Drive in Fungi

POST-DOCTORAL POSITION IN THE EVOLUTION OF MEIOTIC DRIVE

A two-year postdoctoral position is available in the research group of professor Hanna Johannesson, at the Evolutionary Biology Centre (EBC), Uppsala University.

Conflicts arising from selfish genetic elements are important drivers for evolutionary change and innovation, and thus of crucial importance for genetic form and function.  The main goal of this project is to study the evolutionary dynamics of meiotic drive in fungi.  The study system is the Spore killers of Podospora anserina, a filamentous ascomycete. The ultimate aim of our research group is to combine large-scale genomic analyses with theoretical and experimental investigations to study the evolutionary dynamics of this meiotic drive system, both on a short and a long evolutionary timescale. This postdoc project will be developed after the interest of the applicant, but should preferably encompass a combination of experimental and genomic aspects. It will be a part of a collaborative effort within our research group.

Applicants should have a PhD in biology/evolutionary biology. Documented skills in molecular phylogenetics and/or population genetics, experimental and genomic work, especially using fungal model systems, is highly valued.

Start date is flexible, ideally February 1, 2016. The position may be
extended for up to two more years.

Please send your application materials by November 25 to
Hanna.Johannesson@ebc.uu.se. The application shall include: 1) a cover letter stating research interests, 2) a CV, including publication
record, 3) a short (1-2 page) description of research accomplishments, and 4) name and contact information for three references.

Please feel free to contact me at the above listed e-mail with
questions.

Recent animal-associated fungal genome papers

The genomes of five dermatophyte fungi were sequenced and the analyses of their lifestyles presented in a new paper out in mBio in Martinez et al. 2012. The authors were able to identify gene family changes that associate with lifestyle changes including proteases that can degrade keratin suggesting how these species have adapted to obtaining nutrients from an animal host. The continued finding of fungal-specific kinase families in these fungi, extending the observations from previous studies in Coprinopsis and Paracoccidioides on the FunK1 kinase family, makes me hope we will some day get some molecular information on the specificity of these families in addition to these copy number observations.
Another paper published in Genome Research this summer from Emily Troemel‘s lab and the Broad Institute describes the sequencing of two microsporidia species that are natural parasites of Caenorhabditis.The paper reveals some suprising things about Microsporidia evolution including the presence of a clade-specific nucleoside H+ symporter which is only found in bacteria and some eukaryotes and not in any Fungi. The phyletic distribution suggested it was acquired more recently and couple from lateral gene transfer. This acquisition likely helps the microsporidia cells obtain nucleosides from the host since the parasite cannot synthesize these. There is also evidence of evolution of microsporidia-specific secretion signals in the hexokinases which may be a mechanism for delivery of these enzymes into host cells to catalyze rapid growth once inside the host. Many more gems in this paper including phylogenetic placement of the microsporidia from phylogenomic approaches (also see related recent work from Toni Gabaldon‘s lab).

Nuclear Pore Complex studied in thermophilic fungus

ResearchBlogging.orgSometimes choosing a hot lover can make all the difference. In this case, choosing a thermophilic fungus was the right eukaryote for the job to purify stable proteins from the nuclear pore complex and test their interactions. Since high temperatures (60C as compared to what its relative Chaetomium globosum prefers, 24C) will denature proteins, this fungus has evolved the ability to still fold up proteins nicely at those high temperatures. Thus at more standard laboratory room temperature or below, these proteins should be really stable and easier to work with.  This manuscript (not OpenAccess sadly) includes the genome sequence of Chaetomium thermophilum sequenced with 454 FLX and XLR at 24X and assembled into 20 scaffolds – (8 chromosomes expected so they say – and I agree – this is quite good).The used the Celera assembler to make this final assembly for those of you taking notes at home on how to assemble your fungal genomes. The genome is available for download at the authors’s site or at GenBank. Their assembly is quite a bit smaller (28.3 Mb) than the related C. globosum (34.9) or Neurospora crassa genome (41Mb – though the authors use the old version and report 39.2; they also say “*based on the published genome (Galagan et al., 2003), although there is a newer assembly of N. crassa available from Broad, the newer assembly is not annotated for protein coding genes yet.” which is kind of weird because there is an annotated version here). I do wonder if the tendency of repeated elements to be collapsed in the assembly process resulted in a smaller assembly or if this really does have a smaller genome and less genes (~7k genes while Neurospora has ~10k).  Also worth noting that several other thermophilic fungi have been public for a while at the JGI too – Thielavia terrestris and Sporotrichum thermophile and our lab and others are investigating the genome content and how some genome properties like transposons have evolved in these lineages.

The thermophilic adaptation of this fungus has lead to stable proteins which can be studied more easily than mesophilic fungi. They have been able to determine how the nucleoporins (Nups) interact because of the biochemical and structural assays that are possible with the more stable protein complexes. This highlights the value of targeting an experimental system that has the properties needed and the simple and straightforward tactics needed to generate and use the genome sequence (the genome is but a minor note in the findings of this paper).  I can only wonder why none of my de novo genome assemblies go together as nicely as this one, but I’m excited to see this work present new insights into the biology of nuclear pore complexes.

Amlacher, S., Sarges, P., Flemming, D., van Noort, V., Kunze, R., Devos, D., Arumugam, M., Bork, P., & Hurt, E. (2011). Insight into Structure and Assembly of the Nuclear Pore Complex by Utilizing the Genome of a Eukaryotic Thermophile Cell, 146 (2), 277-289 DOI: 10.1016/j.cell.2011.06.039

Ncrassa v5 annotation released

The Missing PieceAs an update to previous post, the N. crassa annotation has been updated to version 5 on the Broad Institute website. Previously the data was not yet available for this update, but as of 8-Mar-2011 it is.  The assembly hasn’t changed but the annotation is updated and includes some fixes to improperly renamed locus names.  On the N. crassa genome site you can see files with the history of loci through this to determine if a locus name was improperly changed in the past. This should be rectified in the currently released annotation, and definitely encourage you to take it for a spin and report back to the Broad Institute if you have any questions.

Neurospora annotation update (v5)

Here is a message from the Broad Institute about a gene annotation update that was made recently in response to an issue that was revealed in the June 2010 release.  This new version is called V5 and should be on its way to GenBank.

Dear Neurospora scientists,

Recently we discovered an issue with the way locus tags were assigned
to our most recent Neurospora gene set, released publicly on the Broad
website in June of 2010. Many genes in this gene set have mismatched
locus numbers compared to the same genes released in February 2010.
Adding to the confusion, both releases were labeled version 4.

To remedy this we have recalled the June locus numbers and released a
new, version 5 gene set. Genes in this set have been numbered to
preserve historical locus numbers (back to the original genbank
release) as much as possible.

Folks who call their favorite genes by their v1, v2 or v3 numbers can
search for them on our web page, which will map them to v5
automatically and accurately. The same will work for most v4 numbers.
Unfortunately, 863 genes have different locus tags in the two v4
releases. If you search for one of them, you will get two hits - the
v5 gene that the February edition mapped to, and the v5 gene that the
June edition mapped to.

Two examples to clarify:

A. Suppose you search for NCU11713.4 on our web page. This query will
retrieve two genes, NCU11688.5 and NCU11713.5. The gene which in the
February release was called NCU11713.4 is the same as NCU11688.5,
while the gene labeled NCU11713.4 in June is the same as NCU11713.5.

B. Searching for NCU11324.4 yields but one hit because that gene, like
most genes, was consistently numbered between the two releases labeled
4.

If you are not sure when you downloaded your genes, the following may
help. If you see any of these locus numbers in your gene set:

NCU00129.4, NCU00457.4, NCU00499.4, NCU00556.4, NCU00627.4,
NCU00685.4, NCU00768.4, NCU00856.4, NCU00986.4, NCU01064.4,
NCU01065.4, NCU01282.4, NCU01299.4, NCU01300.4, NCU01483.4,
NCU01559.4, NCU01560.4, NCU01610.4, NCU01611.4, NCU01664.4,
NCU01665.4, NCU01871.4, NCU01903.4, NCU02200.4, NCU02259.4,
NCU02666.4, NCU02758.4, NCU02837.4, NCU02998.4, NCU03047.4,
NCU03206.4, NCU03773.4, NCU04239.4, NCU04240.4, NCU04518.4,
NCU04519.4, NCU04710.4, NCU04711.4, NCU05275.4, NCU05512.4,
NCU05776.4, NCU06013.4, NCU06370.4, NCU06732.4, NCU07107.4,
NCU07259.4, NCU07260.4, NCU07301.4, NCU07405.4, NCU07856.4,
NCU07857.4, NCU08090.4, NCU08182.4, NCU08323.4, NCU08332.4,
NCU09085.4, NCU09256.4, NCU09257.4, NCU09998.4, NCU10166.4,
NCU10574.4, NCU11040.4, NCU11240.4, NCU11253.4, NCU11376.4,
NCU11390.4, NCU11393.4

then your genes are from the February 2010 gene set. However, if you see

NCU00082.4, NCU00083.4, NCU00084.4, NCU00085.4, NCU00516.4,
NCU01819.4, NCU04299.4, NCU04300.4, NCU04301.4, NCU04302.4,
NCU04303.4, NCU04304.4, NCU04305.4, NCU05000.4, NCU05111.4,
NCU05112.4, NCU05113.4, NCU05114.4, NCU05115.4, NCU05116.4,
NCU05448.4, NCU05452.4, NCU06667.4, NCU07323.4, NCU09066.4,
NCU10179.4, NCU10301.4, NCU10379.4, NCU10383.4, NCU10753.4,
NCU10866.4, NCU10914.4, NCU11068.4, NCU11182.4, NCU12157.4,
NCU12158.4, NCU12159.4, NCU12160.4, NCU12161.4, NCU12162.4,
NCU12163.4, NCU12164.4, NCU12165.4, NCU12166.4, NCU12167.4,
NCU12168.4, NCU12169.4, NCU12170.4, NCU12171.4, NCU12172.4,
NCU12173.4, NCU12174.4, NCU12175.4, NCU12176.4, NCU12177.4,
NCU12178.4, NCU12179.4, NCU12180.4, NCU12181.4, NCU12182.4,
NCU12183.4, NCU12184.4, NCU12185.4, NCU12186.4, NCU12187.4, NCU12188.4

then your genes are from the June 2010 release.

Attached please find five mapping tables which can be used to migrate
locus numbers from any of the previous releases to the latest version
5 locus tags (linked below).

We apologize for any confusion this may cause.
Love,
The Broad Institute

I’ve also uploaded the locus update files which maps between versions of the annotation.

FGSC – a key partner in fungal biology research

FGSC logoAn article about the Fungal Genetics Stock Center written by the curators provides some insight into the 50 year history of this resource. It is a great summary of how the stock center has grown over the years and demonstrates how it is an essential aspect of how research on filamentous fungi is possible. The FGSC staff also provide important infrastructure in organization of meetings like the Neurospora and Fungal Genetics meetings and are also active pursuing their own research.  So don’t forget to cite FGSC in  your talks and (very importantly) papers.

McCluskey K, Wiest A, & Plamann M (2010). The Fungal Genetics Stock Center: a repository for 50 years of fungal genetics research. Journal of Biosciences, 35 (1), 119-26 PMID: 20413916

Methylation to the max!

A new paper from the Zilberman lab at UC Berkeley shows the application of high throughput sequencing to the study of DNA methylation in eukaryotes.  They generate an huge data set of whole genome methylation patterns in several plants, animals, and five fungi including early diverging Zygomycete.

The work was performed using Bisulfite sequencing (Illumina) to capture methylated DNA, RNA-Seq of mRNA. The also performed some ChIP-Seq of H2A.Z on pufferfish to look at the nucleosome positioning in that species. For aligning the reads, they used BowTie to align the bisulfite sequences (though I’d be curious how a new aligner, BRAT, designed for Bisulfite seq reads would perform) to the genome.  They also sequenced mRNA via RNA-Seq to assay gene expression for some of the species.

They find several interesting patterns in animal and fungal genomes.  I’ll highlight one in the fungi. They find an unexpected pattern in U. reesii of reduced CGs in repeats, which shows signatures of a RIP-like process, are also methylated.  This finding is also consistent with observations in Coccidioides (Sharpton et al, Genome Res 2009) that showed depleted CGs pairs in repeats.  Since the phenomenon is also found in Coccidioides genomes this methylation of some repeats is likely not unique to U. reesii but may be important in recent evolution of the Onygenales fungi or the larger Eurotiales fungi.  There are several other interesting findings with the first such study that shows methylation data for Zygomycete fungi and a basidiomycete close to my heart, Coprinopsis.  It will be interesting is to dig deeper into this data and see how the patterns of methylation compare to other genomic features and the mechanisms regulating methylation process.

Zemach, A., McDaniel, I., Silva, P., & Zilberman, D. (2010). Genome-Wide Evolutionary Analysis of Eukaryotic DNA Methylation Science DOI: 10.1126/science.1186366

Hey there fluffy

ResearchBlogging.orgI spy a picture of Neurospora growing on the cover of Genetics this month.  The cover highlights the results from the work of the lab of Luis Corrochano who works on  light regulation in a variety of systems like Neurospora and Phycomyces.  This work describes their work on the fluffy gene which regulates conidiation (production of conidia or asexual spores). They show that an important interplay between an inducer of light response, the White Collar Complex (WCC), and the FLD protein on fluffy.  The data from indicate hat FLD represses fluffy as a response to dark but that this repression is removed in response to light through the action of WCC.

Olmedo, M., Ruger-Herreros, C., & Corrochano, L. (2009). Regulation by Blue Light of the fluffy Gene Encoding a Major Regulator of Conidiation in Neurospora crassa Genetics, 184 (3), 651-658 DOI: 10.1534/genetics.109.109975

A cacophony of comparative genomics papers

A nice series of comparative genomics articles have been published in the last few weeks. The pace of genome sequencing has accelerated to the point that we have lots of sequencing projects coming from individual labs and small consortia not necessarily from genome centers. We are seeing a preview of what next (2nd) generation sequencing will enable and can start to imagine what happens when even cheaper 3rd generation sequencing technologies are applied. I’m behind in reviewing these papers for you, dear reader, but I hope you’ll click through and take a look at some of these papers if you are interested in the topics.

In the following set of papers we have some nice examples of comparative genomics of closely related species and among a clade of species. The papers mentioned below include our work on the human pathogens Coccidioides and Histoplasma (Sharpton et al) studied at several evolutionary distances, a study on Saccharomycetaceae (Souciet et al) clade of yeast species, and a comparison of two species of Candida (Jackson et al): the commensal and opportunistic fungal pathogen Candida albicans with a very closely related species Candida dubliensis.  There is also a nice comparison of strains of Saccharomyces cerevisiae looking at effects of domestication and examples of horizontal transfer.

There is also a report of de novo sequencing of a filamentous fungus using several approaches, traditional Sanger sequencing, 454, and Illumina/Solexa (DiGuistini et al).

Finally, a paper from a few months ago (Ma et al), gives a fantastic look at one of the early branches in the fungal tree – the Mucorales (formerly Zygomycota) – via the genome of Rhizopus oryzae.  This paper is a really excellent example of what we can learn about a group of species by contrasting genomic features in the early branches in the tree with the more well studied Ascomycete and Basidiomycete fungi.  More genome sequences will help us build on these findings and clarify if some of the observations are unique to the lineage or universal aspects of the earliest fungi.

I hope you enjoy!

Novo, M., Bigey, F., Beyne, E., Galeote, V., Gavory, F., Mallet, S., Cambon, B., Legras, J., Wincker, P., Casaregola, S., & Dequin, S. (2009). Eukaryote-to-eukaryote gene transfer events revealed by the genome sequence of the wine yeast Saccharomyces cerevisiae EC1118 Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0904673106 (via J Heitman)

Jackson, A., Gamble, J., Yeomans, T., Moran, G., Saunders, D., Harris, D., Aslett, M., Barrell, J., Butler, G., Citiulo, F., Coleman, D., de Groot, P., Goodwin, T., Quail, M., McQuillan, J., Munro, C., Pain, A., Poulter, R., Rajandream, M., Renauld, H., Spiering, M., Tivey, A., Gow, N., Barrell, B., Sullivan, D., & Berriman, M. (2009). Comparative genomics of the fungal pathogens Candida dubliniensis and C. albicans Genome Research DOI: 10.1101/gr.097501.109

DiGuistini, S., Liao, N., Platt, D., Robertson, G., Seidel, M., Chan, S., Docking, T., Birol, I., Holt, R., Hirst, M., Mardis, E., Marra, M., Hamelin, R., Bohlmann, J., Breuil, C., & Jones, S. (2009). De novo genome sequence assembly of a filamentous fungus using Sanger, 454 and Illumina sequence data. Genome Biology, 10 (9) DOI: 10.1186/gb-2009-10-9-r94 (open access)

Sharpton, T., Stajich, J., Rounsley, S., Gardner, M., Wortman, J., Jordar, V., Maiti, R., Kodira, C., Neafsey, D., Zeng, Q., Hung, C., McMahan, C., Muszewska, A., Grynberg, M., Mandel, M., Kellner, E., Barker, B., Galgiani, J., Orbach, M., Kirkland, T., Cole, G., Henn, M., Birren, B., & Taylor, J. (2009). Comparative genomic analyses of the human fungal pathogens Coccidioides and their relatives Genome Research DOI: 10.1101/gr.087551.108 (open access)

Souciet, J., Dujon, B., Gaillardin, C., Johnston, M., Baret, P., Cliften, P., Sherman, D., Weissenbach, J., Westhof, E., Wincker, P., Jubin, C., Poulain, J., Barbe, V., Segurens, B., Artiguenave, F., Anthouard, V., Vacherie, B., Val, M., Fulton, R., Minx, P., Wilson, R., Durrens, P., Jean, G., Marck, C., Martin, T., Nikolski, M., Rolland, T., Seret, M., Casaregola, S., Despons, L., Fairhead, C., Fischer, G., Lafontaine, I., Leh, V., Lemaire, M., de Montigny, J., Neuveglise, C., Thierry, A., Blanc-Lenfle, I., Bleykasten, C., Diffels, J., Fritsch, E., Frangeul, L., Goeffon, A., Jauniaux, N., Kachouri-Lafond, R., Payen, C., Potier, S., Pribylova, L., Ozanne, C., Richard, G., Sacerdot, C., Straub, M., & Talla, E. (2009). Comparative genomics of protoploid Saccharomycetaceae Genome Research DOI: 10.1101/gr.091546.109 (open access)

Ma, L., Ibrahim, A., Skory, C., Grabherr, M., Burger, G., Butler, M., Elias, M., Idnurm, A., Lang, B., Sone, T., Abe, A., Calvo, S., Corrochano, L., Engels, R., Fu, J., Hansberg, W., Kim, J., Kodira, C., Koehrsen, M., Liu, B., Miranda-Saavedra, D., O’Leary, S., Ortiz-Castellanos, L., Poulter, R., Rodriguez-Romero, J., Ruiz-Herrera, J., Shen, Y., Zeng, Q., Galagan, J., Birren, B., Cuomo, C., & Wickes, B. (2009). Genomic Analysis of the Basal Lineage Fungus Rhizopus oryzae Reveals a Whole-Genome Duplication PLoS Genetics, 5 (7) DOI: 10.1371/journal.pgen.1000549 (open access)

For your reading pleasure

Too much on my plate as of late, so I’m woefully behind on posting much on interesting papers or news.  Here’s a short list of links and papers that are worth a look though.

  • “Evolution of pathogenicity and sexual reproduction in eight Candida genomes” published (Nature)
  • NYT Science article sort of summarizing the good, bad, and ugly of fungi and human interactions
  • Attempts to save amphibians from chytridiomycosis “Riders of a Modern-Day Ark” (PLoS Biology)
  • Looks like Scott Baker with the JGI are in the process of resequencing several classical mutant strains of Phycomyces, Neurospora and Cochliobolus, Cryphonectria for sequence-based mapping of mutants (i.e. here and here and here).