Evolutionary analysis of the female-specific avianW chromosome
Smeds, Linnea; Warmuth, Vera; Bolivar, Paulina; Uebbing, Severin; Burri, Reto; Suh, Alexander; Nater, Alexander; Bures, Stanislav; Garamszegi, Laszlo Z.; Hogner, Silje; Moreno, Juan; Qvarnström, Anna; Ruzic, Milan; Sæther, Stein Are; Sætre, Glenn-Peter; Torok, Janos; Ellegren, Hans
Journal article, Peer reviewed
Date
2015Metadata
Show full item recordCollections
- Publikasjoner fra CRIStin - NINA [2443]
- Scientific publications [1470]
Abstract
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 Wchromosome 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.