title: Between two fern genomes.
abstract: Ferns are the only major lineage of vascular plants not represented by a sequenced nuclear genome. This lack of genome sequence information significantly impedes our ability to understand and reconstruct genome evolution not only in ferns, but across all land plants. Azolla and Ceratopteris are ideal and complementary candidates to be the first ferns to have their nuclear genomes sequenced. They differ dramatically in genome size, life history, and habit, and thus represent the immense diversity of extant ferns. Together, this pair of genomes will facilitate myriad large-scale comparative analyses across ferns and all land plants. Here we review the unique biological characteristics of ferns and describe a number of outstanding questions in plant biology that will benefit from the addition of ferns to the set of taxa with sequenced nuclear genomes. We explain why the fern clade is pivotal for understanding genome evolution across land plants, and we provide a rationale for how knowledge of fern genomes will enable progress in research beyond the ferns themselves.
authors.affiliation: Department of Biology, Box 118525, University of Florida, Gainesville, FL 32611, USA ; Genetics Institute, University of Florida, Box 103610, Gainesville, FL 32611, USA.
authors.forename: Emily B
authors.initials: EB
authors.lastname: Sessa
authors.affiliation: Department of Botany and Plant Pathology, Purdue University, 915 West State Street, West Lafayette, IN 47907, USA.
authors.forename: Jo Ann
authors.initials: JA
authors.lastname: Banks
authors.affiliation: Department of Ecology & Evolutionary Biology, University of Arizona, 1041 East Lowell Street, Tucson, AZ 85721, USA.
authors.forename: Michael S
authors.initials: MS
authors.lastname: Barker
authors.affiliation: Department of Biology, Penn State University, 201 Life Science Building, University Park, PA 16801, USA ; Current address: Department of Biological Science, California State University, 800 N. State College Blvd., Fullerton, CA 92831, USA.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Der
authors.affiliation: Ecology Center and Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Duffy
authors.affiliation: Department of Botany, University of British Columbia, 3529-6720 University Blvd., Vancouver, BC V6T 1Z4, Canada.
authors.forename: Sean W
authors.initials: SW
authors.lastname: Graham
authors.affiliation: National Institute for Basic Biology, 38 Nishigounaka, Myo-daiji-cho, Okazaki 444-8585, Japan.
authors.forename: Mitsuyasu
authors.initials: M
authors.lastname: Hasebe
authors.affiliation: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford OX1 3RB, UK.
authors.forename: Jane
authors.initials: J
authors.lastname: Langdale
authors.affiliation: Department of Biology, Duke University, Post Office Box 90338, Durham, NC 27708, USA.
authors.forename: Fay-Wei
authors.initials: FW
authors.lastname: Li
authors.affiliation: Department of Biology, Box 118525, University of Florida, Gainesville, FL 32611, USA ; Florida Museum of Natural History, Dickinson Hall, University of Florida, Gainesville, FL 32611, USA.
authors.forename: D Blaine
authors.initials: DB
authors.lastname: Marchant
authors.affiliation: Department of Biology, Duke University, Post Office Box 90338, Durham, NC 27708, USA.
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Pryer
authors.affiliation: Department of Zoology, University of British Columbia, 2329 W. Mall, WAITING Vancouver, BC V6T 1Z4, Canada ; Current address: University Herbarium and Department of Integrative Biology, University of California, 1001 Valley Life Sciences Building, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Rothfels
authors.affiliation: Department of Molecular Biosciences, University of Texas, 205 W. 24th Street, Austin, TX 78712, USA.
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Roux
authors.affiliation: Department of Molecular Biosciences, University of Texas, 205 W. 24th Street, Austin, TX 78712, USA.
authors.forename: Mari L
authors.initials: ML
authors.lastname: Salmi
authors.affiliation: Department of Biology, Duke University, Post Office Box 90338, Durham, NC 27708, USA.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Sigel
authors.affiliation: Department of Biology, Box 118525, University of Florida, Gainesville, FL 32611, USA ; Genetics Institute, University of Florida, Box 103610, Gainesville, FL 32611, USA ; Florida Museum of Natural History, Dickinson Hall, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Soltis
authors.affiliation: Genetics Institute, University of Florida, Box 103610, Gainesville, FL 32611, USA ; Florida Museum of Natural History, Dickinson Hall, University of Florida, Gainesville, FL 32611, USA.
authors.forename: Pamela S
authors.initials: PS
authors.lastname: Soltis
authors.affiliation: New York Botanical Garden, 2900 Southern Boulevard, Bronx, NY 10458, USA.
authors.forename: Dennis W
authors.initials: DW
authors.lastname: Stevenson
authors.affiliation: Ecology Center and Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322, USA.
authors.forename: Paul G
authors.initials: PG
authors.lastname: Wolf
keywords: Azolla; Ceratopteris; Comparative analyses; Ferns; Genomics; Land plants; Monilophytes