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Mycological Research News
mycological research 113 (2009) 163–164
journal homepage: www.elsevier.com/locate/mycres
Mycological Research News1 In this issue Fungi in drinking water [Review] (pp. 165–172). Haradamyces foliicola gen. sp. nov. causes a leaf blight in Cornus (pp. 173– 181). Cortinarius sect. Brunnei in North Europe (pp. 182–206). Phaeomollisia piceae gen. sp. nov., a new dark septate conifer needle endophyte (pp. 207–221). The Aspergillus niger het-c incompatability gene (pp. 222–229). Aspergillus flavus pathogenicity in insects (pp. 230–239). Genomic structure of the A mating-type locus in Pholiota nameko (pp. 240–248). A re-evaluation of Phoma-like soybean pathogenic fungi (pp. 249–260). Novel hyphomycete genera on trichomes of cerrado plants (pp. 261–274).
A ‘‘green-beard’’ gene discovered in Saccharomyces cerevisiae The ‘‘green-beard’’ gene is one which enables relatives in a population to recognize each other by some marker, and so behave more altruistically to each other than to other individuals in the population that lack that marker. The gene was so-named by Dawkins (1976) for a hypothetical gene proposed by Hamilton (1964), and such a gene was subsequently discovered in nature, first in the fire ant Solenopsis invicta (Keller & Ross 1998) and then in other organisms including the slime mould Dictyostelium discoideum (Queller et al. 2003). Now, studying the genetics of wild (flocculating) and brewing (non-flocculating) strains of Saccharomyces cerevisiae, Smukalla et al. (2008) have discovered that one of five flocculation celladhesion genes, FLO1, behaves as a ‘‘green-beard’’ gene. Cells with the gene aggregate together in ‘‘flocs’’, while those without it do not, and the differences are visually striking (Queller 2008). The cause and effect relationship was demonstrated by engineering the gene into both strains which had evidently lost the gene during duplication, and also into a normally non-flocculating S. paradoxus causing it to floc. Flocculation is advantageous in yeasts as cells towards the centre of aggregations receive some protection against potentially damaging effects of alcoholic solutions in which they may be growing. Cells lacking FLO1 can become loosely attached to flocs, but then tend to be exploited by ending up in the outer layers
1
where they are more susceptible to damage. This study will add kin-recognition to the reasons for the popularity of S. cerevisiae as an experimental tool amongst evolutionary biologists. Dawkins R, 1976. The Selfish Gene. Oxford University Press, Oxford. Hamilton WD, 1964. The genetical evolution of social behaviour I [and II]. Journal of Theoretical Biology 7: 1–52. Keller L, Ross KG, 1998. Selfish genes: a green beard in the red fire ant. Nature 394: 573–575. Queller DC, 2008. The social side of wild yeast. Nature 456: 589– 590. Queller DC, Ponte E, Bozzaro S, Strassmann JE, 2003. Single-gene geenbeard effects in the social amoeba Dictyostelium discoideum. Science 299: 105–106. Smukalla S, Caldara M, Pochet N, Beauvais A, Guadagnini S, Yan C, Vinces MD, Jansen A, Prevost MC, Latge´ J-P, Fink JR, Foster KR, Verstrepen KJ, 2008. FLO1 is a variable green beard gene that drives biofilm-like cooperation in budding yeast. Cell 135: 726–737.
Aspergillus fumigatus teleomorph in Neosartorya discovered Aspergillus fumigatus is one of the most widespread fungi known, and in addition to occurrences in soils and organic materials it is commonly encountered in human habitations. It is of considerable medical interest not only as a causal agent of ‘‘farmer’s lung’’, asthma and allergies, but further as a cause of invasive infections in immunocompromised individuals. Although the fungus is well-represented in genetic resource collections and has been the subject of numerous experiments, with 37 200 references in Google Scholar2, no ascomata had ever been reported. This has become increasingly a mystery as genome screening has revealed no less than 215 genes implicated in sexual development in this ‘‘asexual’’ fungus (Galagan et al. 2005). Now, from 91 strains of the species from Dublin, O’Gorman et al. (2009) set up crossing experiments with 12 isolates using all possible combinations of opposite mating types and a range of growth media and temperatures. After six months, ascomata producing viable ascospores which germinated to form the asexual stage, the anamoprh, were found in some
Mycological Research News is compiled by the Associate Senior Editor, David L. Hawksworth, Departamento de Biologı´a Vegetal II, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramo´n y Cajal, Ciudad Universitaria, ES-28040 Madrid, Spain (e-mail: [email protected]), to whom items for inclusion should be sent. Unsigned items are by the Associate Senior Editor. 2 http://scholar.google.co.uk/scholar?q¼aspergillusþfumigatus&hl¼en&lr¼&btnG¼Search; interrogated 31 December 2008.
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pairings, in some cases with over 100 ascomata per plate. The sexual stage, the teleomorph, belonged to the genus Neosartorya and the new binomial N. fumigata was therefore coined for this as currently permitted by the Code. The authors speculate that the species might be experiencing a slow decline in fertility and that the discovery of the sexual stage in isolates all from one region may be ‘‘a rare subset of fertile isolates’’. However, as there is genetic evidence that the species comprises one global recombining population, perhaps the reason is the methods O’Gorman et al. employed and their patience in waiting for six months; most mycologists working with Aspergillus species rarely grow the fungi on agar plates for more than a few weeks. It would be interesting to see whether ascomata could also be obtained from pairing isolates from other local populations of the fungus. It is also possible that the fungus does form ascomata in nature, but in habitats or under conditions where mycologists rarely search. The recognition of a sexual stage for A. fumigatus enhances knowledge of the biology and basis for the recombination already recognized in the fungus. The extent to which this discovery may help our understanding of the diseases in which it is implicated remains to be seen, but it has occasioned excitement amongst medical mycologists and fungal geneticists. The formal naming of the teleomorph does, however, now mean that the name Neosartorya fumigata is available for application to the fungus as a whole, inclusive of the Aspergillus fumigatus asexual stage. It is therefore open to researchers to use the name N. fumigata in publications dealing with the asexual stage alone. Mechanisms to restrict or end such dual naming of fungi with pleomorphic life-cycles are currently under discussion by a special committee appointed by the International Botanical Congress in 2005. It would therefore be prudent, in the interests of scientific communication and to avoid confusion in diagnoses and literature, for mycologists reporting or publishing on this fungus to continue to use the name A. fumigatus regardless of whether ascomata are formed in their isolates. This is already common practice amongst fungal geneticists who work on Aspergillus nidulans, where the name Emericella nidulans is not generally used. The Nature paper was published online on 30 November 2008. However, under the Code, new scientific names are not ruled as effectively published until hard copies are printed and distributed; in this case the issue of Nature dated 22 January 2009. The date ‘‘2009’’ is therefore the one to be used in formal citations of this paper in taxonomic works. Galagan JE, Calvo SE, Cuomo C, Mai L-J, Wortman JR, Batzoglou S, Lee S-I, Bastu¨rkmen M, Christina C, Spevak CC, Clutterbuck J, Kapitonov V, Jurka J, Scazzocchio C, Farman M, Butler J, Purcell S, Harris S, Braus GH, Draht O, Busch S, D’Enfert C, Bouchier C, Goldman GH, Bell-Pedersen D, Griffiths-Jones S, Doonan JH, Yu J, Vienken K, Pain A, Freitag M, Selker EU, Archer DB, Pen˜alva MA, Oakley BR, Momany M, Tanaka T, Kumagai Y, Asai K, Machida M, Nierman WC, Denning DW, Caddick M, Hynes M, Paoletti M, Fischer R, Miller B, Dyer P, Sachs MS, Osmani SA, Birren BW, 2005. Sequencing of
D. L. Hawksworth
Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae. Nature 438: 1105–1115. O’Gorman CM, Fuller HT, Dyer PS, 2009. Discovery of a sexual cycle in the opportunistic fungal pathogen Aspergillus fumigatus. Nature 457: 471–474.
Taxonomic information in Mycological Research Readers should note that since the change of editorial arrangements for Mycological Research on 1 November 2008, cognate changes in copy editing by Elsevier, and elimination of editorial checking of proofs, the presentation of nomenclatural material in taxonomic papers is no longer being scrutinized as it was before that date. Inconsistencies in presentations, and in some cases practices contrary to recommendations or usage in the Code, will therefore be found in some published papers while alternative arrangements to avoid such occurrences are being explored by the new Senior Editors.
New scientific names in this issue Cortinarius albogaudis sp. nov. C. clarobrunneus comb. nov. (syn. Cortinarius brunneus var. clarobrunneus) C. caesiobrunneus sp. nov. C. carabus sp. nov. C. cicindela sp. nov. Echinoconidiophorum gen. nov. E. cerradense sp. nov. Globoconidiopsis gen. nov. G. cerradensis sp. nov. Globoconidium gen. nov. G. cerradense sp. nov. Haradamyces gen. nov. H. foliicola sp. nov. Helminthosporiomyces gen. nov. H. cerradensis sp. nov. Microtrichosphaera gen. nov. M. cerradensis sp. nov. Phaeomollisia gen. nov. P. piceae sp. nov. Phialocephala glacialis sp. nov. Phragmoconidium gen. nov. P. cerradense sp. nov. Trichomatoclava gen. nov. T. cerradensis sp. nov. Vesiculohyphomyces gen. nov. V. cerradensis sp. nov.
0953-7562/$ – see front matter doi:10.1016/j.mycres.2009.01.001
journal homepage: www.elsevier.com/locate/mycres
Mycological Research News1 In this issue Fungi in drinking water [Review] (pp. 165–172). Haradamyces foliicola gen. sp. nov. causes a leaf blight in Cornus (pp. 173– 181). Cortinarius sect. Brunnei in North Europe (pp. 182–206). Phaeomollisia piceae gen. sp. nov., a new dark septate conifer needle endophyte (pp. 207–221). The Aspergillus niger het-c incompatability gene (pp. 222–229). Aspergillus flavus pathogenicity in insects (pp. 230–239). Genomic structure of the A mating-type locus in Pholiota nameko (pp. 240–248). A re-evaluation of Phoma-like soybean pathogenic fungi (pp. 249–260). Novel hyphomycete genera on trichomes of cerrado plants (pp. 261–274).
A ‘‘green-beard’’ gene discovered in Saccharomyces cerevisiae The ‘‘green-beard’’ gene is one which enables relatives in a population to recognize each other by some marker, and so behave more altruistically to each other than to other individuals in the population that lack that marker. The gene was so-named by Dawkins (1976) for a hypothetical gene proposed by Hamilton (1964), and such a gene was subsequently discovered in nature, first in the fire ant Solenopsis invicta (Keller & Ross 1998) and then in other organisms including the slime mould Dictyostelium discoideum (Queller et al. 2003). Now, studying the genetics of wild (flocculating) and brewing (non-flocculating) strains of Saccharomyces cerevisiae, Smukalla et al. (2008) have discovered that one of five flocculation celladhesion genes, FLO1, behaves as a ‘‘green-beard’’ gene. Cells with the gene aggregate together in ‘‘flocs’’, while those without it do not, and the differences are visually striking (Queller 2008). The cause and effect relationship was demonstrated by engineering the gene into both strains which had evidently lost the gene during duplication, and also into a normally non-flocculating S. paradoxus causing it to floc. Flocculation is advantageous in yeasts as cells towards the centre of aggregations receive some protection against potentially damaging effects of alcoholic solutions in which they may be growing. Cells lacking FLO1 can become loosely attached to flocs, but then tend to be exploited by ending up in the outer layers
1
where they are more susceptible to damage. This study will add kin-recognition to the reasons for the popularity of S. cerevisiae as an experimental tool amongst evolutionary biologists. Dawkins R, 1976. The Selfish Gene. Oxford University Press, Oxford. Hamilton WD, 1964. The genetical evolution of social behaviour I [and II]. Journal of Theoretical Biology 7: 1–52. Keller L, Ross KG, 1998. Selfish genes: a green beard in the red fire ant. Nature 394: 573–575. Queller DC, 2008. The social side of wild yeast. Nature 456: 589– 590. Queller DC, Ponte E, Bozzaro S, Strassmann JE, 2003. Single-gene geenbeard effects in the social amoeba Dictyostelium discoideum. Science 299: 105–106. Smukalla S, Caldara M, Pochet N, Beauvais A, Guadagnini S, Yan C, Vinces MD, Jansen A, Prevost MC, Latge´ J-P, Fink JR, Foster KR, Verstrepen KJ, 2008. FLO1 is a variable green beard gene that drives biofilm-like cooperation in budding yeast. Cell 135: 726–737.
Aspergillus fumigatus teleomorph in Neosartorya discovered Aspergillus fumigatus is one of the most widespread fungi known, and in addition to occurrences in soils and organic materials it is commonly encountered in human habitations. It is of considerable medical interest not only as a causal agent of ‘‘farmer’s lung’’, asthma and allergies, but further as a cause of invasive infections in immunocompromised individuals. Although the fungus is well-represented in genetic resource collections and has been the subject of numerous experiments, with 37 200 references in Google Scholar2, no ascomata had ever been reported. This has become increasingly a mystery as genome screening has revealed no less than 215 genes implicated in sexual development in this ‘‘asexual’’ fungus (Galagan et al. 2005). Now, from 91 strains of the species from Dublin, O’Gorman et al. (2009) set up crossing experiments with 12 isolates using all possible combinations of opposite mating types and a range of growth media and temperatures. After six months, ascomata producing viable ascospores which germinated to form the asexual stage, the anamoprh, were found in some
Mycological Research News is compiled by the Associate Senior Editor, David L. Hawksworth, Departamento de Biologı´a Vegetal II, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza Ramo´n y Cajal, Ciudad Universitaria, ES-28040 Madrid, Spain (e-mail: [email protected]), to whom items for inclusion should be sent. Unsigned items are by the Associate Senior Editor. 2 http://scholar.google.co.uk/scholar?q¼aspergillusþfumigatus&hl¼en&lr¼&btnG¼Search; interrogated 31 December 2008.
164
pairings, in some cases with over 100 ascomata per plate. The sexual stage, the teleomorph, belonged to the genus Neosartorya and the new binomial N. fumigata was therefore coined for this as currently permitted by the Code. The authors speculate that the species might be experiencing a slow decline in fertility and that the discovery of the sexual stage in isolates all from one region may be ‘‘a rare subset of fertile isolates’’. However, as there is genetic evidence that the species comprises one global recombining population, perhaps the reason is the methods O’Gorman et al. employed and their patience in waiting for six months; most mycologists working with Aspergillus species rarely grow the fungi on agar plates for more than a few weeks. It would be interesting to see whether ascomata could also be obtained from pairing isolates from other local populations of the fungus. It is also possible that the fungus does form ascomata in nature, but in habitats or under conditions where mycologists rarely search. The recognition of a sexual stage for A. fumigatus enhances knowledge of the biology and basis for the recombination already recognized in the fungus. The extent to which this discovery may help our understanding of the diseases in which it is implicated remains to be seen, but it has occasioned excitement amongst medical mycologists and fungal geneticists. The formal naming of the teleomorph does, however, now mean that the name Neosartorya fumigata is available for application to the fungus as a whole, inclusive of the Aspergillus fumigatus asexual stage. It is therefore open to researchers to use the name N. fumigata in publications dealing with the asexual stage alone. Mechanisms to restrict or end such dual naming of fungi with pleomorphic life-cycles are currently under discussion by a special committee appointed by the International Botanical Congress in 2005. It would therefore be prudent, in the interests of scientific communication and to avoid confusion in diagnoses and literature, for mycologists reporting or publishing on this fungus to continue to use the name A. fumigatus regardless of whether ascomata are formed in their isolates. This is already common practice amongst fungal geneticists who work on Aspergillus nidulans, where the name Emericella nidulans is not generally used. The Nature paper was published online on 30 November 2008. However, under the Code, new scientific names are not ruled as effectively published until hard copies are printed and distributed; in this case the issue of Nature dated 22 January 2009. The date ‘‘2009’’ is therefore the one to be used in formal citations of this paper in taxonomic works. Galagan JE, Calvo SE, Cuomo C, Mai L-J, Wortman JR, Batzoglou S, Lee S-I, Bastu¨rkmen M, Christina C, Spevak CC, Clutterbuck J, Kapitonov V, Jurka J, Scazzocchio C, Farman M, Butler J, Purcell S, Harris S, Braus GH, Draht O, Busch S, D’Enfert C, Bouchier C, Goldman GH, Bell-Pedersen D, Griffiths-Jones S, Doonan JH, Yu J, Vienken K, Pain A, Freitag M, Selker EU, Archer DB, Pen˜alva MA, Oakley BR, Momany M, Tanaka T, Kumagai Y, Asai K, Machida M, Nierman WC, Denning DW, Caddick M, Hynes M, Paoletti M, Fischer R, Miller B, Dyer P, Sachs MS, Osmani SA, Birren BW, 2005. Sequencing of
D. L. Hawksworth
Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae. Nature 438: 1105–1115. O’Gorman CM, Fuller HT, Dyer PS, 2009. Discovery of a sexual cycle in the opportunistic fungal pathogen Aspergillus fumigatus. Nature 457: 471–474.
Taxonomic information in Mycological Research Readers should note that since the change of editorial arrangements for Mycological Research on 1 November 2008, cognate changes in copy editing by Elsevier, and elimination of editorial checking of proofs, the presentation of nomenclatural material in taxonomic papers is no longer being scrutinized as it was before that date. Inconsistencies in presentations, and in some cases practices contrary to recommendations or usage in the Code, will therefore be found in some published papers while alternative arrangements to avoid such occurrences are being explored by the new Senior Editors.
New scientific names in this issue Cortinarius albogaudis sp. nov. C. clarobrunneus comb. nov. (syn. Cortinarius brunneus var. clarobrunneus) C. caesiobrunneus sp. nov. C. carabus sp. nov. C. cicindela sp. nov. Echinoconidiophorum gen. nov. E. cerradense sp. nov. Globoconidiopsis gen. nov. G. cerradensis sp. nov. Globoconidium gen. nov. G. cerradense sp. nov. Haradamyces gen. nov. H. foliicola sp. nov. Helminthosporiomyces gen. nov. H. cerradensis sp. nov. Microtrichosphaera gen. nov. M. cerradensis sp. nov. Phaeomollisia gen. nov. P. piceae sp. nov. Phialocephala glacialis sp. nov. Phragmoconidium gen. nov. P. cerradense sp. nov. Trichomatoclava gen. nov. T. cerradensis sp. nov. Vesiculohyphomyces gen. nov. V. cerradensis sp. nov.
0953-7562/$ – see front matter doi:10.1016/j.mycres.2009.01.001