Phylogenetic relationships among ascomycetes: evidence from an RNA polymerse II subunit.

In an effort to establish a suitable alternative to the widely used 18S rRNA system for molecular systematics of fungi, we examined the nuclear gene RPB2, encoding the second largest subunit of RNA polymerase II. Because RPB2 is a single-copy gene of large size with a modest rate of evolutionary change, it provides good phylogenetic resolution of Ascomycota. While the RPB2 and 18S rDNA phylogenies were highly congruent, the RPB2 phylogeny did result in much higher bootstrap support for all the deeper branches within the orders and for several branches between orders of the Ascomycota. There are several strongly supported phylogenetic conclusions. The Ascomycota is composed of three major lineages: Archiascomycetes, Saccharomycetales, and Euascomycetes. Within the Euascomycetes, plectomycetes, and pyrenomycetes are monophyletic groups, and the Pleosporales and Dothideales are distinct sister groups within the Loculoascomycetes. We confirm the placement of Neolecta within the Archiascomycetes, suggesting that fruiting body formation and forcible discharge of ascospores were characters gained early in the evolution of the Ascomycota. These findings show that a slowly evolving protein-coding gene such as RPB2 is useful for diagnosing phylogenetic relationships among fungi.

[1]  O. Eriksson,et al.  Molecular evidence for recognizing the Chaetothyriales , 1998 .

[2]  B. Hall,et al.  Usefulness of RNA polymerase II coding sequences for estimation of green plant phylogeny. , 1998, Molecular biology and evolution.

[3]  B D Hall,et al.  The origin of red algae: implications for plastid evolution. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[4]  J. W. Taylor,et al.  Phylogenetic origins of the asexual mycorrhizal symbiont Cenococcum geophilum Fr. and other mycorrhizal fungi among the ascomycetes. , 1996, Molecular phylogenetics and evolution.

[5]  M. Berbee.  Loculoascomycete origins and evolution of filamentous ascomycete morphology based on 18S rRNA gene sequence data. , 1996, Molecular biology and evolution.

[6]  S. Landvik.  Neolecta, a fruit-body-producing genus of the basal ascomycetes, as shown by SSU and LSU rDNA sequences , 1996 .

[7]  J. Spatafora.  Ascomal evolution of filamentous ascomycetes: evidence from molecular data , 1995 .

[8]  M. Berbee,et al.  From 18S ribosomal sequence data to evolution of morphology among the fungi , 1995 .

[9]  C. J. Robnett,et al.  MOLECULAR RELATIONSHIPS AMONG HYPHAL ASCOMYCETOUS YEASTS AND YEASTLIKE TAXA , 1995 .

[10]  H. Klenk,et al.  Location of Protist Lineages in a Phylogenetic Tree Inferred from Sequences of DNA-dependent RNA Polymerases , 1995 .

[11]  J. W. Taylor,et al.  Phylogeny of Discomycetes and early radiations of the apothecial Ascomycotina inferred from SSU rDNA sequence data. , 1995, Experimental mycology.

[12]  H. Nishida,et al.  Archiascomycetes: detection of a major new lineage within the Ascomycota , 1994 .

[13]  A. Sidow,et al.  A molecular evolutionary framework for eukaryotic model organisms , 1994, Current Biology.

[14]  A. Gargas,et al.  18S rRNA gene sequences and supraordinal classification of the Erysiphales , 1994 .

[15]  J. Spatafora,et al.  Cladistic Analysis of Partial ssrDNA Sequences among Unitunicate Perithecial Ascomycetes and Its Implications on the Evolution of Centrum Development , 1994 .

[16]  J. Spatafora,et al.  MOLECULAR SYSTEMATICS OF UNITUNICATE PERITHECIAL ASCOMYCETES: THE CLAVICIPITALES-HYPOCREALES CONNECTION , 1993 .

[17]  H. Nishida,et al.  Phylogenetic relationships among Taphrina, Saitoella, and other higher fungi. , 1993, Molecular biology and evolution.

[18]  O. Eriksson.  Outline of the Ascomycetes-1993 , 1993 .

[19]  William R. Taylor,et al.  The rapid generation of mutation data matrices from protein sequences , 1992, Comput. Appl. Biosci..

[20]  Rainer Fuchs,et al.  CLUSTAL V: improved software for multiple sequence alignment , 1992, Comput. Appl. Biosci..

[21]  J. W. Taylor,et al.  Two ascomycete classes based on fruiting-body characters and ribosomal DNA sequence. , 1992, Molecular biology and evolution.

[22]  David L. Hawksworth,et al.  The fungal dimension of biodiversity: magnitude, significance, and conservation , 1991 .

[23]  B. Hall,et al.  The RET1 gene of yeast encodes the second-largest subunit of RNA polymerase III. Structural analysis of the wild-type and ret1-1 mutant alleles. , 1991, The Journal of biological chemistry.

[24]  R. Honegger.  Functional Aspects of the Lichen Symbiosis , 1991 .

[25]  M. E. Barr.  Prodromus to nonlichenized, pyrenomycetous members of class Hymenoascomycetes , 1990 .

[26]  J. Rogers,et al.  Prodromus to class loculoascomycetes , 1990 .

[27]  A. R. Templeton,et al.  PHYLOGENETIC INFERENCE FROM RESTRICTION ENDONUCLEASE CLEAVAGE SITE MAPS WITH PARTICULAR REFERENCE TO THE EVOLUTION OF HUMANS AND THE APES , 1983, Evolution; international journal of organic evolution.

[28]  M. E. Barr.  The Ascomycete Connection , 1983 .

[29]  Joseph Felsenstein,et al.  A likelihood approach to character weighting and what it tells us about parsimony and compatibility , 1981 .

[30]  David L. Hawksworth,et al.  Ainsworth & Bisby's Dictionary of the Fungi , 1972 .

[31]  L. Haley.  Introductory Mycology , 1953, The Yale Journal of Biology and Medicine.

[32]  E. S. Luttrell.  The Ascostromatic Ascomycetes , 1955 .

[33]  J. A. Nannfeldt.  Studien über die Morphologie und Systematik der nicht-lichenisierten inoperculaten Discomyceten , 1932 .