TY - JOUR
T1 - Conservation of Sex-Linked Markers among Conspecific Populations of a Viviparous Skink, Niveoscincus ocellatus, Exhibiting Genetic and Temperature-Dependent Sex Determination
AU - Hill, Peta
AU - Burridge, Christopher
AU - EZAZ, Tariq
AU - Wapstra, Erik
N1 - Funding Information:
We thank the following people: G. Cunningham and L. Fitzpatrick for field collection and valuable contributions and discussions, A. Kilian and Diversity Arrays Technology for sequencing support. We thank the Holsworth Wildlife Research Endowment and the Australasian and Pacific Science Foundation for their contributions to this research. All guidelines and procedures for the use of animals were approved by the University of Tasmania animal ethics committee (no. A0012087). This work was supported by the Australian Research Council (FT110100597).
Publisher Copyright:
© The Author(s) 2018.
PY - 2018/4/1
Y1 - 2018/4/1
N2 - 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.
AB - 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.
KW - GSD
KW - Heterogamety
KW - Population divergence
KW - Reptiles
KW - Sex chromosomes
KW - TSD
UR - http://www.scopus.com/inward/record.url?scp=85053386366&partnerID=8YFLogxK
U2 - 10.1093/gbe/evy042
DO - 10.1093/gbe/evy042
M3 - Article
SN - 1759-6653
VL - 10
SP - 1079
EP - 1087
JO - Genome Biology and Evolution
JF - Genome Biology and Evolution
IS - 4
ER -