PT  - JOURNAL ARTICLE
AU  - Aline Muyle
AU  - Niklaus Zemp
AU  - Cécile Fruchard
AU  - Radim Cegan
AU  - Jan Vrana
AU  - Clothilde Deschamps
AU  - Raquel Tavares
AU  - Roman Hobza
AU  - Franck Picard
AU  - Alex Widmer
AU  - Gabriel AB Marais
TI  - Genomic imprinting mediates dosage compensation in a young plant XY system
AID  - 10.1101/179044
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 179044
4099  - http://biorxiv.org/content/early/2017/12/02/179044.short
4100  - http://biorxiv.org/content/early/2017/12/02/179044.full
AB  - During the evolution of sex chromosomes, the Y degenerates and its expression gets reduced relative to the X and autosomes. Various dosage compensation mechanisms that recover ancestral expression levels in males have been described in animals. However, the early steps in the evolution of dosage compensation remain unknown, and dosage compensation outside of the animal kingdom is poorly understood. Here, we studied the evolutionarily young XY system of the plant Silene latifolia. We show that dosage compensation is achieved in this plant by a genomic imprinting mechanism where the maternal X chromosome is upregulated in both males and females. This is the first time such a situation is observed in any organism. It could be nonoptimal for females and may reflect an early stage of dosage compensation evolution, which strikingly resemble the first stage of the path proposed by Ohno for the evolution of X inactivation in mammals.One Sentence Summary In the plant Silene latifolia, reduced expression from the Y chromosome is compensated by upregulation of the maternal X chromosome in both sexes.