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Evolutionary analysis of the female-specific avian W chromosome

The typically repetitive nature of the sex-limited chromosome means that it is often excluded from or poorly covered in genome assemblies, hindering studies of evolutionary and population genomic processes in non-recombining chromosomes. Here, we present a draft assembly of the non-recombining regio...

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Detalles Bibliográficos
Autores principales: Smeds, Linnéa, Warmuth, Vera, Bolivar, Paulina, Uebbing, Severin, Burri, Reto, Suh, Alexander, Nater, Alexander, Bureš, Stanislav, Garamszegi, Laszlo Z., Hogner, Silje, Moreno, Juan, Qvarnström, Anna, Ružić, Milan, Sæther, Stein-Are, Sætre, Glenn-Peter, Török, Janos, Ellegren, Hans
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Pub. Group 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4468903/
https://www.ncbi.nlm.nih.gov/pubmed/26040272
http://dx.doi.org/10.1038/ncomms8330
Descripción
Sumario:The typically repetitive nature of the sex-limited chromosome means that it is often excluded from or poorly covered in genome assemblies, hindering studies of evolutionary and population genomic processes in non-recombining chromosomes. Here, we present a draft assembly of the non-recombining region of the collared flycatcher W chromosome, containing 46 genes without evidence of female-specific functional differentiation. Survival of genes during W chromosome degeneration has been highly non-random and expression data suggest that this can be attributed to selection for maintaining gene dose and ancestral expression levels of essential genes. Re-sequencing of large population samples revealed dramatically reduced levels of within-species diversity and elevated rates of between-species differentiation (lineage sorting), consistent with low effective population size. Concordance between W chromosome and mitochondrial DNA phylogenetic trees demonstrates evolutionary stable matrilineal inheritance of this nuclear–cytonuclear pair of chromosomes. Our results show both commonalities and differences between W chromosome and Y chromosome evolution.