title: Rapid Y degeneration and dosage compensation in plant sex chromosomes.
abstract: The nonrecombining regions of animal Y chromosomes are known to undergo genetic degeneration, but previous work has failed to reveal large-scale gene degeneration on plant Y chromosomes. Here, we uncover rapid and extensive degeneration of Y-linked genes in a plant species, Silene latifolia, that evolved sex chromosomes de novo in the last 10 million years. Previous transcriptome-based studies of this species missed unexpressed, degenerate Y-linked genes. To identify sex-linked genes, regardless of their expression, we sequenced male and female genomes of S. latifolia and integrated the genomic contigs with a high-density genetic map. This revealed that 45% of Y-linked genes are not expressed, and 23% are interrupted by premature stop codons. This contrasts with X-linked genes, in which only 1.3% of genes contained stop codons and 4.3% of genes were not expressed in males. Loss of functional Y-linked genes is partly compensated for by gene-specific up-regulation of X-linked genes. Our results demonstrate that the rate of genetic degeneration of Y-linked genes in S. latifolia is as fast as in animals, and that the evolutionary trajectories of sex chromosomes are similar in the two kingdoms.
authors.affiliation: Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom.
authors.forename: Alexander S T
authors.initials: AS
authors.lastname: Papadopulos
authors.affiliation: Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Chester
authors.affiliation: Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom.
authors.forename: Kate
authors.initials: K
authors.lastname: Ridout
authors.affiliation: Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom dmitry.filatov@plants.ox.ac.uk.
authors.forename: Dmitry A
authors.initials: DA
authors.lastname: Filatov
mesh_terms: D032461:Chromosomes, Plant; D004303:Dosage Compensation, Genetic; D008040:Genetic Linkage; D010944:Plants / Q000235:genetics*; D012730:Sex Chromosomes; D029751:Silene / Q000235:genetics*
keywords: Y degeneration; dosage compensation; gene expression; plants; sex chromosome evolution