Differentiation of sex chromosomes and karyotypic evolution in the eye-lid geckos (Squamata: Gekkota: Eublepharidae), a group with different modes of sex determination
Abstract
The eyelid geckos (family Eublepharidae) include both species with temperature-dependent sex determination and species with genotypic sex determination (GSD). In this study, we present data on karyotypes and chromosomal characteristics in 12 species covering all genera of the family.
Phylogenetic mapping of chromosomal changes showed a long evolutionary stasis of karyotypes with all acrocentric chromosomes followed by numerous chromosomal rearrangements in the ancestors of two lineages. We have found heteromorphic sex chromosomes in only one species, which suggests that sex chromosomes in most GSD species of the eyelid geckos are not morphologically differentiated.
The sexual difference in karyotype was detected only in Coleonyx elegans which has a multiple sex chromosome system (X1X2Y).