title: Expansion of the molecular and morphological diversity of Acanthamoebidae (Centramoebida, Amoebozoa) and identification of a novel life cycle type within the group.
abstract: Acanthamoebidae is a "family" level amoebozoan group composed of the genera Acanthamoeba, Protacanthamoeba, and very recently Luapeleamoeba. This clade of amoebozoans has received considerable attention from the broader scientific community as Acanthamoeba spp. represent both model organisms and human pathogens. While the classical composition of the group (Acanthamoeba + Protacanthamoeba) has been well accepted due to the morphological and ultrastructural similarities of its members, the Acanthamoebidae has never been highly statistically supported in single gene phylogenetic reconstructions of Amoebozoa either by maximum likelihood (ML) or Bayesian analyses.
  
  
  
  Here we show using a phylogenomic approach that the Acanthamoebidae is a fully supported monophyletic group within Amoebozoa with both ML and Bayesian analyses. We also expand the known range of morphological and life cycle diversity found in the Acanthamoebidae by demonstrating that the amoebozoans "Protostelium" arachisporum, Dracoamoeba jormungandri n. g. n. sp., and Vacuolamoeba acanthoformis n.g. n.sp., belong within the group. We also found that "Protostelium" pyriformis is clearly a species of Acanthamoeba making it the first reported sporocarpic member of the genus, that is, an amoeba that individually forms a walled, dormant propagule elevated by a non-cellular stalk. Our phylogenetic analyses recover a fully supported Acanthamoebidae composed of five genera. Two of these genera (Acanthamoeba and Luapeleameoba) have members that are sporocarpic.
  
  
  
  Our results provide high statistical support for an Acanthamoebidae that is composed of five distinct genera. This study increases the known morphological diversity of this group and shows that species of Acanthamoeba can include spore-bearing stages. This further illustrates the widespread nature of spore-bearing stages across the tree of Amoebozoa.
  
  
  
  This article was reviewed by Drs. Eugene Koonin, Purificacion Lopez-Garcia and Sandra Baldauf. Sandra Baldauf was nominated by Purificacion Lopez-Garcia, an Editorial Board member.
authors.affiliation: Department of Biological Sciences, Mississippi State University, PO BOX GY, Mississippi State, MS, 39762, USA.|Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS, USA.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Tice
authors.affiliation: Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA.
authors.forename: Lora L
authors.initials: LL
authors.lastname: Shadwick
authors.affiliation: Institute of Zoology, Department of Terrestrial Ecology, University of Cologne, Cologne, Germany.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Fiore-Donno
authors.affiliation: Institute of Zoology, Department of Terrestrial Ecology, University of Cologne, Cologne, Germany.|Department of Terrestrial Ecology, Netherlands Institute for Ecology, Wageningen, The Netherlands.
authors.forename: Stefan
authors.initials: S
authors.lastname: Geisen
authors.affiliation: Department of Biological Sciences, Mississippi State University, PO BOX GY, Mississippi State, MS, 39762, USA.|Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS, USA.
authors.forename: Seungho
authors.initials: S
authors.lastname: Kang
authors.affiliation: Department of Biological Sciences, Mississippi State University, PO BOX GY, Mississippi State, MS, 39762, USA.
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Schuler
authors.affiliation: Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA.
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Spiegel
authors.affiliation: Department of Biological Sciences, University of Arkansas, Fayetteville, AR, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Wilkinson
authors.affiliation: Institute of Zoology, Department of Terrestrial Ecology, University of Cologne, Cologne, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bonkowski
authors.affiliation: Institute of Zoology, Department of Terrestrial Ecology, University of Cologne, Cologne, Germany.
authors.forename: Kenneth
authors.initials: K
authors.lastname: Dumack
authors.affiliation: Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, 05508-090, Brazil.
authors.forename: Daniel J G
authors.initials: DJ
authors.lastname: Lahr
authors.affiliation: Penard Labs, Berlin, Germany.
authors.forename: Eckhard
authors.initials: E
authors.lastname: Voelcker
authors.affiliation: Penard Labs, Berlin, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Clauß
authors.affiliation: College of Resources and Environmental Sciences, China Agricultural University, 100193, Beijing, People's Republic of China.
authors.forename: Junling
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Biological Sciences, Mississippi State University, PO BOX GY, Mississippi State, MS, 39762, USA. matthew.brown@msstate.edu.|Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS, USA. matthew.brown@msstate.edu.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Brown
mesh_terms: D016842:Acanthopodina / Q000145:classification* / Q000166:cytology / Q000235:genetics; D019143:Evolution, Molecular; D010802:Phylogeny; D015800:Protozoan Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D015800:Protozoan Proteins
keywords: Acanthamoeba; Amoebozoa; Protist; Protostelids; Protosteloid amoebae