title: An eight-gene molecular phylogeny of the Kickxellomycotina, including the first phylogenetic placement of Asellariales.
abstract: Kickxellomycotina is a recently described subphylum encompassing four zygomycete orders (Asellariales, Dimargaritales, Harpellales, Kickxellales). These fungi are united by the formation of disciform septal pores containing lenticular plugs. Morphological diversification and life history evolution has made the relationships within and among the four orders difficult to resolve on those grounds alone. Here we infer the phylogeny of the Kickxellomycotina based on an eight-gene supermatrix including both ribosomal rDNA (18S, 28S, 5.8S) and protein sequences (MCM7, TSR1, RPB1, RPB2, β-tubulin). The results of this study demonstrate that Kickxellomycotina is monophyletic and related to members of the Zoopagomycotina. Eight unique clades are distinguished in the Kickxellomycotina, including the four defined orders (Asellariales, Dimargaritales, Harpellales, Kickxellales) as well as four genera previously placed within two of these orders (Barbatospora, Orphella, Ramicandelaber, Spiromyces). Dimargaritales and Ramicandelaber are the earliest diverging members of the subphylum, although the relationship between these taxa remains uncertain. The remaining six clades form a monophyletic group, with Barbatospora diverging first. The next split divides the remaining members of the subphylum into two subclades: (i) Asellariales and Harpellales and (ii) Kickxellales, Orphella and Spiromyces. Estimation of ancestral states for four potentially informative morphological and ecological characters reveals that arthropod endosymbiosis might have been an important factor in the early evolution of the Kickxellomycotina.
authors.affiliation: Boise State University, Department of Biological Sciences, Boise, Idaho 83725-1515.
authors.forename: Eric D
authors.initials: ED
authors.lastname: Tretter
authors.affiliation: Boise State University, Department of Biological Sciences, Boise, Idaho 83725-1515.
authors.forename: Eric M
authors.initials: EM
authors.lastname: Johnson
authors.affiliation: University of Florida, Department of Plant Pathology, Gainesville, Florida 32611-0680.
authors.forename: Gerald L
authors.initials: GL
authors.lastname: Benny
authors.affiliation: University of Kansas, Department of Ecology & Evolutionary Biology, Lawrence, Kansas 66045-7534.
authors.forename: Robert W
authors.initials: RW
authors.lastname: Lichtwardt
authors.affiliation: Boise State University, Department of Biological Sciences, Boise, Idaho 83725-1515.
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Boise State University, Department of Biological Sciences, Boise, Idaho 83725-1515.
authors.forename: Prasanna
authors.initials: P
authors.lastname: Kandel
authors.affiliation: Boise State University, Department of Biological Sciences, Boise, Idaho 83725-1515.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Novak
authors.affiliation: Boise State University, Department of Biological Sciences, Boise, Idaho 83725-1515.
authors.forename: James F
authors.initials: JF
authors.lastname: Smith
authors.affiliation: Boise State University, Department of Biological Sciences, Boise, Idaho 83725-1515 merlinwhite@boisestate.edu.
authors.forename: Merlin M
authors.initials: MM
authors.lastname: White
mesh_terms: D000818:Animals; D001181:Arthropods / Q000382:microbiology; D001483:Base Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D019143:Evolution, Molecular; D005656:Fungal Proteins / Q000235:genetics; D005658:Fungi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D008969:Molecular Sequence Data; D016533:Mycological Typing Techniques; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013172:Spores, Fungal; D013559:Symbiosis
chemical_list: D004271:DNA, Fungal; D004275:DNA, Ribosomal; D005656:Fungal Proteins
keywords: arthropod symbiosis; clades; molecular phylogenies; mycophyletic; zoopagomycotina