Geckos (Gekkota) are a highly diversified group of lizards with an exceptional diversity in sex-determining systems. Despite this intriguing documented variability, data on sex determination in many lineages is still scarce. Here, we document the previously overlooked heteromorphic ZZ/ZW sex chromosomes in the thick-tailed gecko, Underwoodisaurus milii, a member of the ancient lineage of pygopodoid geckos. The finding of female heterogamety within pygopodoid geckos was unexpected, as until now only male heterogamety and environmental sex determination have been reported in this group, and female heterogamety was known only in distantly related gecko families separated from the pygopodoid geckos around 150 million years ago. The W chromosome in U. milii is highly heterochromatic and contains a large number of telomeric-like repeats comparable to around 50% of all telomeric-like sequences present in male genomes. The accumulation of these repeats might have been responsible for the considerable size expansion of the W chromosome in comparison to the Z chromosome. The heteromorphic ZZ/ZW sex chromosomes with accumulated telomeric-like repeats in the thick-tailed geckos further illustrate the exceptional diversity of sex-determining systems in geckos and add important information to our understanding of the evolution and phylogeny of sex-determining systems in reptiles.

Department of Ecology Faculty of Science Charles University Prague Prague Czech Republic

Citace poskytuje Crossref.org

Cytogenetic Analysis of Seven Species of Gekkonid and Phyllodactylid Geckos

ZZ/ZW Sex Chromosomes in the Madagascar Girdled Lizard, Zonosaurus madagascariensis (Squamata: Gerrhosauridae)

Comparison of Karyotypes in Two Hybridizing Passerine Species: Conserved Chromosomal Structure but Divergence in Centromeric Repeats

Sex chromosome evolution among amniotes: is the origin of sex chromosomes non-random?

Are Geckos Special in Sex Determination? Independently Evolved Differentiated ZZ/ZW Sex Chromosomes in Carphodactylid Geckos

With or Without W? Molecular and Cytogenetic Markers are Not Sufficient for Identification of Environmentally-Induced Sex Reversal in the Bearded Dragon

Poorly differentiated XX/XY sex chromosomes are widely shared across skink radiation

Independent Evolution of Sex Chromosomes in Eublepharid Geckos, A Lineage with Environmental and Genotypic Sex Determination

Patterns of Sex Chromosome Differentiation in Spiders: Insights from Comparative Genomic Hybridisation

Evidence of Interspecific Chromosomal Diversification in Rainbowfishes (Melanotaeniidae, Teleostei)

Interstitial Telomeric Repeats Are Rare in Turtles

Evolutionary Variability of W-Linked Repetitive Content in Lacertid Lizards

Cytogenetic Analysis Did Not Reveal Differentiated Sex Chromosomes in Ten Species of Boas and Pythons (Reptilia: Serpentes)

Adaptive Radiation from a Chromosomal Perspective: Evidence of Chromosome Set Stability in Cichlid Fishes (Cichlidae: Teleostei) from the Barombi Mbo Lake, Cameroon

Conserved sex chromosomes and karyotype evolution in monitor lizards (Varanidae)

Characterization of the karyotype and accumulation of repetitive sequences in Australian Darling hardyhead Craterocephalus amniculus (Atheriniformes, Teleostei)

Deciphering the Origin and Evolution of the X1X2Y System in Two Closely-Related Oplegnathus Species (Oplegnathidae and Centrarchiformes)

Evolutionary Dynamics of the W Chromosome in Caenophidian Snakes

Evolution of Karyotypes in Chameleons

Stable Cretaceous sex chromosomes enable molecular sexing in softshell turtles (Testudines: Trionychidae)