词条 | Podospora anserina |
释义 |
| regnum = Fungi | divisio = Ascomycota | subdivisio = Pezizomycotina | classis = Sordariomycetes | ordo = Sordariales | familia = Lasiosphaeriaceae | genus = Podospora | species = P. anserina | binomial = Podospora anserina | binomial_authority = }} Podospora anserina is a model filamentous, ascomycete fungus. It is non-pathogenic to humans.[1] It is a herbivore dung-colonizing (coprophilous) fungus. It is pseudohomothallic. TaxonomyPodospora anserina had the original name Malinvernia anserina Rabenhorst (1857) and Podospora anserina was subsequently published in Niessl von Mayendorf, G. 1883: Ueber die Theilung der Gattung Sordaria. Hedwigia 22: 153-156, which is used today to reference the common laboratory strain therefrom, namely, 'Niessl'. It is also known as Pleurage anserina (Ces.) Kuntze.[2][3] Genetics of P. anserina were characterized in Rizet and Engelmann (1949) and reviewed by Esser (1974). P. anserina is estimated to have diverged from N. crassa 75 million years ago based on 18s rRNA and protein orthologous share 60-70% homology.[4]NCBI Taxonomy ID: 5145,[5] MycoBank # 100818[6] Gene cluster orthologs between Aspergillus nidulans and Podospora anserina have 63% identical primary amino acid sequence (even those these species are from distinct classes) and the average amino acid of compared proteomes is 10% less, giving rise to hypotheses of distinct species yet shared genes ResearchPodospora as a model organism to study genetics, aging (senescence, cell degeneration), ascomycete development, heterokaryon incompatibility (Mating in fungi),[7] prion (disease), and mitochondrial and peroxisomal physiology.[8] Podospora is well culturable in lab (for example, on/in complex (full) potato dextrose or cornmeal agar/broth or even synthetic medium), and, using modern molecular tools, easy to manipulate. Its optimal growth temperature is 25-27 °C. Strains
AgingPodospora anserina has a definite life span and shows phenotypically senescence (slower growth, less aerial hyphae and increased pigment production in distal hyphae), however, isolates show either increased life span or immortality. To study the process of aging many genetic manipulations to produce immortal strains or increase life-span have been done. In general, the mitochondrion and mitochondrial chromosome is investigated (note that animals, closely related to fungi, contain similar organelles like mitochondria). This is because during respiration reactive oxygen species are produced that limit the life span and over time defective mitochondrial DNA can accumulate.[14][15] With this knowledge, much focus turned to nutrition availability, respiration (ATP synthesis) and oxidases, like cytochrome c oxidase. Carotenoids, pigments also found in plants and provide health benefits to humans,[16] are known to be in fungi like Podospora's divergent ancestor Neurospora crassa. In N. crassa (and other fungi) cartenoids al genes, namely focused provide UV radiation protection. Overexpressed of al-2 Podospora anserina increased life span by 31%.[17] Calorie restriction studies show that decreased nutrition, like sugar, increase life span (likely due to slower metabolism and thus decreased reactive oxygen species production or induced survival genes). Also, intracellular copper levels were found to be correlated with growth. This was studied in Grisea-deleted and ex1-deleted strains, as well as in a wild type s strain. Podospora without Grisea, a cooper transcription factor, had decreased intracellular copper levels which lead to use of an alternative respiratory pathway that consequently produced less oxidative stress.[18]Heterokaryon incompatibilityThe following genes, both allelic and nonallelic, are found to be involved in vegetative incompatibility (only those cloned and characterized are listed): het-c, het-c, het-s, idi-2, idi-1, idi-3, mod-A, mode-D, mod-E, psp-A. Podospora anserina contains at least 9 het loci.[19] EnzymesPodospora anserina is known to produce laccases, a type of phenoloxidase.[20]GeneticsOriginal genetic studies by gel electrophoresis led to the finding of the genome size, ca. 35 megabases, with 7 chromosomes and 1 mitochondrial chromosome. In the 1980s the mitochondrial chromosome was sequenced. Then in 2003 a pilot study was initiated to sequence regions bordering chromosome V`s centromere using BAC clones and direct sequencing.[21] In 2008, a 10x whole genome draft sequence was published.[22] The genome size is now estimated to be 35-36 megabases.[23] Genetic manipulation in fungi is difficult due to low homologous recombination efficiency and ectopic integrations (insertion of gene at undesirable location)[24] and thus a hindrance in genetic studies (allele replacement and knockouts).[25] Although in 2005, a method for gene deletion (knock-outs) was developed based on a model for Aspergillus nidulans that involved cosmid plasmid transformation, a better system for Podospora was developed in 2008 by using a strain that lacked nonhomologous end joining proteins (Ku (protein), known in Podospora as PaKu70). This method claimed to have 100% of transformants undergo desired homologous recombination leading to allelic replacement (after the transformation, the PaKu70 deletion can be restored by crossing over with a wild-type strain to yield progeny with only the targeted gene deletion or allelic exchange (e.g. point mutation)).[26] MorphologyMorphology depends on the specific strain. {{Empty section|date=May 2014}}Secondary metabolitesIt is well known that many organisms across all domains produce secondary metabolites and within the kingdom fungi there is no exception, as fungi are known to be prolific in this regard. Product mining was well underway in the 1990s for the genus Podospora. Specifically for Podospora anserina, two new natural products classified as pentaketides, specifically derivatives of benzoquinones, were discovered; these showed antifungal, antibacterial, and cytotoxic activities.[27] Horizontal gene transfer is common in bacteria and between prokaryotes and eukaryotes yet is more rare between eukaryotic organisms. Between fungi, secondary metabolite clusters are good candidates for HGT. For example, a functional ST gene cluster that produces sterigmatocystin was found in Podospora anserina and originally derived from Aspergillus. This cluster is well-conserved, notably the transcription-factor binding sites. Sterigmatocystin itself is toxic and is a precursor to another toxic metabolite, aflatoxin.[28] See also
References1. ^"Podospora anserina: a model filamentous fungus" {{Taxonbar|from=Q3393119}}2. ^Memoirs of the Torrey Botanical Club (1902) 3. ^{{Cite web | url=http://www.mycobank.org/Biolomics.aspx?Table=Mycobank&MycoBankNr_=100818 | title=Podospora anserina}} 4. ^The genome sequence of the model ascomycete fungus Podospora anserina 5. ^{{Cite web | url=https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&id=5145 | title=Taxonomy Browser}} 6. ^{{Cite web | url=http://www.mycobank.org/Biolomics.aspx?Table=Mycobank&MycoBankNr_=100818 | title=Podospora anserina}} 7. ^The transcriptional response to nonself in the fungus Podospora anserina. 8. ^Gene deletion and allelic replacement in the Wlamentous fungus Podospora anserina 9. ^Genetic and molecular analysis of a long-lived strain of Podospora anserina. 10. ^Genes Inhibiting Senescence in the Ascomycete Podospora anserina 11. ^The mitochondrial plasmid pAL2-1 reduces calorierestriction mediated life span extension in the filamentous fungus Podospora anserina 2004 12. ^Copper-Modulated Gene Expression and Senescence in the Filamentous Fungus Podospora anserina 13. ^Copper-Modulated Gene Expression and Senescence in the Filamentous Fungus Podospora anserina 14. ^The mitochondrial plasmid pAL2-1 reduces calorie restriction mediated life span extension in the filamentous fungus Podospora anserina 2004 15. ^GENETIC DISSECTION OF COMPLEX BIOLOGICAL TRAITS; THE LIFESPAN EXTENDING EFFECT OF CALORIE RESTRICTION IN THE FILAMENTOUS FUNGUS PODOSPORA ANSERINA 16. ^The role of carotenoids in human health 17. ^Carotenoids and carotenogenic genes in Podospora anserina: engineering of the carotenoid composition extends the life span of the mycelium 18. ^Copper-Modulated Gene Expression and Senescence in the Filamentous Fungus Podospora anserina 19. ^David Moore. Essential Fungal Genetics. page 40 20. ^THE PHENOLOXIDASES * OF THE ASCOMYCETE PODOSPORA ANSERZNA. COMMUNICATION VI. GENETIC REGULATION OF THE FORMATION OF LACCASE 21. ^Characterization of the genomic organization of the region bordering the centromere of chromosome V of Podospora anserina by direct sequencing. 22. ^The genome sequence of the model ascomycete fungus Podospora anserina 23. ^The genome sequence of the model ascomycete fungus Podospora anserina 24. ^Relationship of vector insert sizeto homologous integration during transformationof Neurospora crassa with the cloned am (GDH) gene 25. ^Gene deletion and allelic replacement in the Wlamentous fungus Podospora anserina 26. ^Gene deletion and allelic replacement in the Wlamentous fungus Podospora anserina 27. ^Anserinones A and B: new antifungal and antibacterial benzoquinones from the coprophilous fungus Podospora anserina. 28. ^{{cite journal|url = http://www.sciencedirect.com/science/article/pii/S0960982210016519 | doi=10.1016/j.cub.2010.12.020 | pmid=21194949 | volume=21 | issue=2 | title=Horizontal Transfer of a Large and Highly Toxic Secondary Metabolic Gene Cluster between Fungi | year=2011 | journal=Current Biology | pages=134–139 | last1 = Slot | first1 = Jason C. | last2 = Rokas | first2 = Antonis}} 1 : Lasiosphaeriaceae |
随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识,基本涵盖了大多数领域的百科知识,是一部内容自由、开放的电子版国际百科全书。