Vertebrates possess diverse sex-determining systems, which differ in evolutionary stability among particular groups. It has been suggested that poikilotherms possess more frequent turnovers of sex chromosomes than homoiotherms, whose effective thermoregulation can prevent the emergence of the sex reversals induced by environmental temperature. Squamate reptiles used to be regarded as a group with an extensive variability in sex determination; however, we document how the rather old radiation of lizards from the genus Anolis, known for exceptional ecomorphological variability, was connected with stability in sex chromosomes. We found that 18 tested species, representing most of the phylogenetic diversity of the genus, share the gene content of their X chromosomes. Furthermore, we discovered homologous sex chromosomes in species of two genera (Sceloporus and Petrosaurus) from the family Phrynosomatidae, serving here as an outgroup to Anolis. We can conclude that the origin of sex chromosomes within iguanas largely predates the Anolis radiation and that the sex chromosomes of iguanas remained conserved for a significant part of their evolutionary history. Next to therian mammals and birds, Anolis lizards therefore represent another adaptively radiated amniote clade with conserved sex chromosomes. We argue that the evolutionary stability of sex-determining systems may reflect an advanced stage of differentiation of sex chromosomes rather than thermoregulation strategy.

Department of Ecology Faculty of Science Charles University Prague Viničná 7 12844 Praha 2 Czech Republic

Citace poskytuje Crossref.org

Sex Chromosome Turnovers and Stability in Snakes

Heteromorphic ZZ/ZW sex chromosomes sharing gene content with mammalian XX/XY are conserved in Madagascan chameleons of the genus Furcifer

Do male and female heterogamety really differ in expression regulation? Lack of global dosage balance in pygopodid geckos

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

Large-scale comparative analysis of cytogenetic markers across Lepidoptera

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

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

ZZ/ZW Sex Determination with Multiple Neo-Sex Chromosomes is Common in Madagascan Chameleons of the Genus Furcifer (Reptilia: Chamaeleonidae)

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

Genome of the Komodo dragon reveals adaptations in the cardiovascular and chemosensory systems of monitor lizards

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)

Mammalian X homolog acts as sex chromosome in lacertid lizards

Evolutionary stability of sex chromosomes in snakes

Female heterogamety in Madagascar chameleons (Squamata: Chamaeleonidae: Furcifer): differentiation of sex and neo-sex chromosomes

Interstitial Telomeric Motifs in Squamate Reptiles: When the Exceptions Outnumber the Rule

Low rate of interchromosomal rearrangements during old radiation of gekkotan lizards (Squamata: Gekkota)

Sex determination in Madagascar geckos of the genus Paroedura (Squamata: Gekkonidae): are differentiated sex chromosomes indeed so evolutionary stable?

Novel X-linked genes revealed by quantitative polymerase chain reaction in the green anole, Anolis carolinensis