title: Female sterility associated with increased clonal propagation suggests a unique combination of androdioecy and asexual reproduction in populations of Cardamine amara (Brassicaceae).
abstract: OBJECTIVE
  The coexistence of hermaphrodites and female-sterile individuals, or androdioecy, has been documented in only a handful of plants and animals. This study reports its existence in the plant species Cardamine amara (Brassicaceae), in which female-sterile individuals have shorter pistils than seed-producing hermaphrodites.
  
  
  METHODS
  Morphological analysis, in situ manual pollination, microsatellite genotyping and differential gene expression analysis using Arabidopsis microarrays were used to delimit variation between female-sterile individuals and hermaphrodites.
  
  
  RESULTS
  Female sterility in C. amara appears to be caused by disrupted ovule development. It was associated with a 2.4- to 2.9-fold increase in clonal propagation. This made the pollen number of female-sterile genets more than double that of hermaphrodite genets, which fulfils a condition of co-existence predicted by simple androdioecy theories. When female-sterile individuals were observed in wild androdioecious populations, their ramet frequencies ranged from 5 to 54 %; however, their genet frequencies ranged from 11 to 29 %, which is consistent with the theoretically predicted upper limit of 50 %.
  
  
  CONCLUSIONS
  The results suggest that a combination of sexual reproduction and increased asexual proliferation by female-sterile individuals probably explains the invasion and maintenance of female sterility in otherwise hermaphroditic populations. To our knowledge, this is the first report of the coexistence of female sterility and hermaphrodites in the Brassicaceae.
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: Andrew
authors.initials: A
authors.lastname: Tedder
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: Matthias
authors.initials: M
authors.lastname: Helling
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: John R
authors.initials: JR
authors.lastname: Pannell
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: Rie
authors.initials: R
authors.lastname: Shimizu-Inatsugi
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Kawagoe
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: Julia
authors.initials: J
authors.lastname: van Campen
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan.
authors.forename: Jun
authors.initials: J
authors.lastname: Sese
authors.affiliation: Institute of Evolutionary Biology and Environmental Studies and Institute of Plant Biology, University of Zurich, Winterthurerstrasse 190, CH-8057, Switzerland, Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland, Center for Ecological Research (CER), Kyoto University, 2-509-3, Hirano, Otsu, Shiga 520-2113, Japan and Computational Biology Research Center (CBRC), National Institute of Advanced Industrial Science and Technology (AIST) Koto-ku, Tokyo, 135-0064, Japan kentaro.shimizu@ieu.uzh.ch.
authors.forename: Kentaro K
authors.initials: KK
authors.lastname: Shimizu
mesh_terms: D031217:Cardamine / Q000235:genetics / Q000502:physiology*; D005838:Genotype; D018895:Microsatellite Repeats / Q000235:genetics; D056771:Ovule / Q000235:genetics / Q000502:physiology; D051479:Plant Infertility; D011058:Pollen / Q000235:genetics / Q000502:physiology; D054817:Pollination; D012098:Reproduction; D012100:Reproduction, Asexual; D012639:Seeds / Q000235:genetics / Q000502:physiology
keywords: Arabidopsis thaliana; Brassicaceae; Cardamine amara; androdioecy; asexual reproduction; clonal propagation; female sterility; reduced male fertility