Conservation of sex-linked markers among conspecific populations of a viviparous skink, Niveoscincus occllatus, exhibiting genetic and temperature-dependent sex determination
Sex determination systems are exceptionally diverse and have undergone multiple and independent evolutionary transitions among species, particularly reptiles. However, the mechanisms underlying these transitions have not been established. Here, we tested for differences in sex-linked markers in the only known reptile that is polymorphic for sex determination system, the spotted snow skink, Niveoscincus ocellatus, to quantify the genomic differences that have accompanied this transition. In a highland population, sex is determined genetically, whereas in a lowland population, offspring sex ratio is influenced by temperature. We found a similar number of sex-linked loci in each population, including shared loci, with genotypes consistent with male heterogamety (XY). However, population-specific linkage disequilibrium suggests greater differentiation of sex chromosomes in the highland population. Our results suggest that transitions between sex determination systems can be facilitated by subtle genetic differences.
Funding
Australia and Pacific Science Foundation
History
Publication title
Genome Biology and Evolution
Volume
10
Issue
4
Pagination
1079-1087
ISSN
1759-6653
Department/School
School of Natural Sciences
Publisher
Oxford University Press
Place of publication
United Kingdom
Rights statement
Copyright 2018 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/