title: Compensation of Dosage-Sensitive Genes on the Chicken Z Chromosome.
abstract: In many diploid species, sex determination is linked to a pair of sex chromosomes that evolved from a pair of autosomes. In these organisms, the degeneration of the sex-limited Y or W chromosome causes a reduction in gene dose in the heterogametic sex for X- or Z-linked genes. Variations in gene dose are detrimental for large chromosomal regions when they span dosage-sensitive genes, and many organisms were thought to evolve complete mechanisms of dosage compensation to mitigate this. However, the recent realization that a wide variety of organisms lack complete mechanisms of sex chromosome dosage compensation has presented a perplexing question: How do organisms with incomplete dosage compensation avoid deleterious effects of gene dose differences between the sexes? Here we use expression data from the chicken (Gallus gallus) to show that ohnologs, duplicated genes known to be dosage-sensitive, are preferentially dosage-compensated on the chicken Z chromosome. Our results indicate that even in the absence of a complete and chromosome wide dosage compensation mechanism, dosage-sensitive genes are effectively dosage compensated on the Z chromosome.
authors.affiliation: Department of Genetics Evolution and Environment, University College London, London, United Kingdom fabian.zimmer.12@ucl.ac.uk.
authors.forename: Fabian
authors.initials: F
authors.lastname: Zimmer
authors.affiliation: Department of Genetics Evolution and Environment, University College London, London, United Kingdom.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Harrison
authors.affiliation: Department of Genetics Evolution and Environment, University College London, London, United Kingdom Department of Ecology and Evolution & Center for Integrative Genomics, University of Lausanne, Biophore 1015, Lausanne, Switzerland Swiss Institute of Bioinformatics, Biophore, 1015 Lausanne, Switzerland.
authors.forename: Christophe
authors.initials: C
authors.lastname: Dessimoz
authors.affiliation: Department of Genetics Evolution and Environment, University College London, London, United Kingdom.
authors.forename: Judith E
authors.initials: JE
authors.lastname: Mank
mesh_terms: D000818:Animals; D002645:Chickens / Q000235:genetics*; D004303:Dosage Compensation, Genetic; D005260:Female; D018628:Gene Dosage; D020440:Gene Duplication; D008297:Male; D012730:Sex Chromosomes / Q000235:genetics*; D019849:Sex Determination Processes
keywords: dosage sensitivity; ohnologs; sex chromosomes; whole genome duplication