UCL Discovery
UCL home » Library Services » Electronic resources » UCL Discovery

Recent sex chromosome divergence despite ancient dioecy in the willow Salix viminalis

Pucholt, P; Wright, AE; Conze, LL; Mank, JE; Berlin, S; (2017) Recent sex chromosome divergence despite ancient dioecy in the willow Salix viminalis. Molecular Biology and Evolution , 34 (8) pp. 1991-2001. 10.1093/molbev/msx144. Green open access

[thumbnail of Mank_msx144.pdf]
Preview
Text
Mank_msx144.pdf

Download (2MB) | Preview

Abstract

Sex chromosomes can evolve when recombination is halted between a pair of chromosomes, and this can lead to degeneration of the sex-limited chromosome. In the early stages of differentiation sex chromosomes are homomorphic, and even though homomorphic sex chromosomes are very common throughout animals and plants, we know little about the evolutionary forces shaping these types of sex chromosomes. We used DNA- and RNA-Seq data from females and males to explore the sex chromosomes in the female heterogametic willow, Salix viminalis, a species with ancient dioecy but with homomorphic sex chromosomes. We detected no major sex differences in read coverage in the SD region, indicating that the W region has not significantly degenerated. However, SNP densities in the SD region are higher in females compared to males, indicating very recent recombination suppression, followed by the accumulation of sex-specific SNPs. Interestingly, we identified two female-specific scaffolds that likely represent W-chromosome-specific sequence. We show that genes located in the SD region display a mild excess of male-biased expression in sex-specific tissue, and we use allele-specific gene expression analysis to show that this is the result of masculinization of expression on the Z chromosome rather than degeneration of female-expression on the W chromosome. Together, our results demonstrate that insertion of small DNA fragments and accumulation of sex-biased gene expression can occur before the detectable decay of the sex-limited chromosome.

Type: Article
Title: Recent sex chromosome divergence despite ancient dioecy in the willow Salix viminalis
Open access status: An open access version is available from UCL Discovery
DOI: 10.1093/molbev/msx144
Publisher version: http://doi.org/10.1093/molbev/msx144
Language: English
Additional information: Copyright © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Keywords: sex chromosomes, masculinization, sex biased gene expression, allele-specific expression
UCL classification: UCL
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences
UCL > Provost and Vice Provost Offices > School of Life and Medical Sciences > Faculty of Life Sciences > Div of Biosciences > Genetics, Evolution and Environment
URI: https://discovery.ucl.ac.uk/id/eprint/1551557
Downloads since deposit
118Downloads
Download activity - last month
Download activity - last 12 months
Downloads by country - last 12 months

Archive Staff Only

View Item View Item