Identification of sex-specific molecular markers using restriction site associated DNA sequencing (RAD-seq)

A major barrier to evolutionary studies of sex determination and sex chromosomes has been a lack of information on the types of sex-determining mechanisms that occur among different species. This is particularly problematic in groups where most species lack visually heteromorphic sex chromosomes, such as fish, amphibians and reptiles, because cytogenetic analyses will fail to identify the sex chromosomes in these species. We describe the use of restriction site associated DNA (RAD) sequencing, or RAD-seq, to identify sex-specific molecular markers and subsequently determine whether a species has male or female heterogamety. To test the accuracy of this technique we examined the lizard Anolis carolinensis. We performed RAD-seq on seven male and ten female A. carolinensis and found one male-specific molecular marker. Anolis carolinensis has previously been shown to possess male heterogamety and the recently published A. carolinensis genome facilitated characterization of the sex-specific ...