title: The Capsella rubella genome and the genomic consequences of rapid mating system evolution.
abstract: The shift from outcrossing to selfing is common in flowering plants, but the genomic consequences and the speed at which they emerge remain poorly understood. An excellent model for understanding the evolution of self fertilization is provided by Capsella rubella, which became self compatible <200,000 years ago. We report a C. rubella reference genome sequence and compare RNA expression and polymorphism patterns between C. rubella and its outcrossing progenitor Capsella grandiflora. We found a clear shift in the expression of genes associated with flowering phenotypes, similar to that seen in Arabidopsis, in which self fertilization evolved about 1 million years ago. Comparisons of the two Capsella species showed evidence of rapid genome-wide relaxation of purifying selection in C. rubella without a concomitant change in transposable element abundance. Overall we document that the transition to selfing may be typified by parallel shifts in gene expression, along with a measurable reduction of purifying selection.
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Tanja
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authors.lastname: Slotte
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Hazzouri
authors.forename: J Arvid
authors.initials: JA
authors.lastname: Ågren
authors.forename: Daniel
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authors.lastname: Koenig
authors.forename: Florian
authors.initials: F
authors.lastname: Maumus
authors.forename: Ya-Long
authors.initials: YL
authors.lastname: Guo
authors.forename: Kim
authors.initials: K
authors.lastname: Steige
authors.forename: Adrian E
authors.initials: AE
authors.lastname: Platts
authors.forename: Juan S
authors.initials: JS
authors.lastname: Escobar
authors.forename: L Killian
authors.initials: LK
authors.lastname: Newman
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Terezie
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authors.lastname: Mandáková
authors.forename: Emilio
authors.initials: E
authors.lastname: Vello
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Smith
authors.forename: Stefan R
authors.initials: SR
authors.lastname: Henz
authors.forename: Joshua
authors.initials: J
authors.lastname: Steffen
authors.forename: Shohei
authors.initials: S
authors.lastname: Takuno
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Brandvain
authors.forename: Graham
authors.initials: G
authors.lastname: Coop
authors.forename: Peter
authors.initials: P
authors.lastname: Andolfatto
authors.forename: Tina T
authors.initials: TT
authors.lastname: Hu
authors.forename: Mathieu
authors.initials: M
authors.lastname: Blanchette
authors.forename: Richard M
authors.initials: RM
authors.lastname: Clark
authors.forename: Hadi
authors.initials: H
authors.lastname: Quesneville
authors.forename: Magnus
authors.initials: M
authors.lastname: Nordborg
authors.forename: Brandon S
authors.initials: BS
authors.lastname: Gaut
authors.forename: Martin A
authors.initials: MA
authors.lastname: Lysak
authors.forename: Jerry
authors.initials: J
authors.lastname: Jenkins
authors.forename: Jane
authors.initials: J
authors.lastname: Grimwood
authors.forename: Jarrod
authors.initials: J
authors.lastname: Chapman
authors.forename: Simon
authors.initials: S
authors.lastname: Prochnik
authors.forename: Shengqiang
authors.initials: S
authors.lastname: Shu
authors.forename: Daniel
authors.initials: D
authors.lastname: Rokhsar
authors.forename: Jeremy
authors.initials: J
authors.lastname: Schmutz
authors.forename: Detlef
authors.initials: D
authors.lastname: Weigel
authors.forename: Stephen I
authors.initials: SI
authors.lastname: Wright
mesh_terms: D017360:Arabidopsis / Q000235:genetics; D029687:Capsella / Q000235:genetics*; D019143:Evolution, Molecular; D005306:Fertilization / Q000235:genetics* / Q000502:physiology; D017343:Genes, Plant; D018745:Genome, Plant / Q000502:physiology; D008969:Molecular Sequence Data; D054817:Pollination / Q000235:genetics* / Q000502:physiology; D057945:Self-Fertilization / Q000235:genetics; D017422:Sequence Analysis, DNA; D013997:Time Factors